Lw520c, Lw560 And Lw560h Operation Manual.doc

PREFACE

This operation and maintenance manual is specially written to give the user a general idea of how to operate maintenance and manage the LW520 Wheel Loader. Information on performance, operation, construction, maintenance and adjustment of the LW520 loader is briefly given in this manual for the reference of operators, maintainers and technical administrators. Due to continuous improvements on the structure and performance of our machines, the user should note that there may be a little difference between the contents of this manual and the latest products of our factory. Any remarks concerning the operation and design of this loader or on this manual will be much appreciated. Please inform us at any time so that we may make further improvements on the quality of the products and serve the user better.

CONTENTS Chapter 1 Applications & main performance and parameter ……………………2 …………………………………………………………………………2 1.1 Applications 1.2 Main performance and parameter………………………………………………2 ……………………………………………………………………2 1.3 Standard installs Chapter 2 Operation and function ………………………………………………………5 2.1 Controlling mechanism and instruments ……………………………………5 2.2 Break-in of a new loader ………………………………………………………6 2.3 Operation of the machine ………………………………………………………7 2.4 Lubrication of the machine ……………………………………………………13 Chapter 3 Main assembly structure and its maintenance ………………………14 3.1 Diesel engine ……………………………………………………………………………14

3.2 Torque converter & transmission ………………………………………………14 3.3 Drive axles ………………………………………………………………………………26 3.4 Transmission shaft ……………………………………………………………………27 3.5 Brake system ……………………………………………………………………………28 ……………………………………………………………………32 3.6 Hydraulic system 3.7 Steering system …………………………………………………………………………38 3.8 Gearchange system ……………………………………………………………………41 ………………………………………………………………………………42 3.9 Implement ………………………………………………………………………………42 3.10 Chassis 3.11 Air conditioning system ………………………………………………………43 3.12 Electrical and instrument system …………………………………………43 Chapter 4 Periodical maintenance ……………………………………………………44 ………………………………………………………47 4.1 General description ………………………………………………………47 4.2 Attention-getting items ………………………………………………………48 4.3 Periodical maintenance Chapter 5 Probable malfunction and remedy ………………………………………50 5.1 Torque converter & transmission ………………………………………………50 5.2 Brake system ……………………………………………………………………………51 ……………………………………………………………………52 5.3 Hydraulic system ……………………………………………………………………… 5.4 Steering system 53 …………………………………………………………………… Chapter 6 Safety Items 56 ……………………………………………………… Chapter 7 General Notices of Safety 58 Chapter 8 Operating Precautions Safety……………………………………………………60 Chapter 9 Precautions for maintenance……………………………………………………64 Chapter 10 Safety Items in Operating Wheel Loader………………………………………66 ……………………………………………66 10.1 General notices of safety 10.2 Precautions before starting the engine ……………………………68 10.3 Precautions after starting the engine and working ……………69 …………………………………………………………………71 10.4 Vehicle parking 10.5 Precaution in the Process of Maintenance……………………………72 10.6 Operating when machine is lifting and transporting…………………74

Sketch map of principal dimensions

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Sketch map of transmission system CHAPTER 1 APPLICATION & MAIN PERFORMANCE AND PARAMETER 1.1 Applications This machine is a larger version of the wheel loaders that are used mainly in loading and unloading loose materials. It is suitable for loading and unloading, bulldozing, lifting, towing and other operations in mine fields, building construction sites, road construction projects, steel and iron works etc. It is a multi-purpose and highly efficient construction machine. 1.2 Main performance and parameter Bucket capacity 3m3 Rating loading capacity 5000kg Arm lifting time (under rating load) 7s Bucket forward tilting time (empty) 2.5s Traveling speed: Forward 1st gear 0～10km/h Forward 2nd gear 0～34km/h Reverse gear 0～13km/h Maximum traction (be fully loaded) 155KN Maximum gradeability 30° Minimum turning radius: Outside of rear whee1 5745mm Outside of bucket 6675mm Dimensions: Overall length (bucket on ground) 7785mm Overall width (outside of wheel) 2820mm Bucket width 3000mm Overall height (top of cab) 3500mm Wheelbase 3200mm Tread 2200mm Minimum ground clearance 450mm Maximum dumping height (dumping reach 1050mm) 3205mm Total weight (cab included) 16500kg Seat of driver: locate in the front of rear frame 1.3 Standard scheme 1.3.1 Diesel engine Model: WD615.61AG26/X6130G27 Structure: Water cooling in-line 4-cycle direct injection Number of cylinders: 6 Cylinder’s inner diameter and stroke: 126×130mm Piston displacement: 9.726L Compression ratio: 15.5 Rated output: 162kW /2200rpm (hour rating) Maximum torque: 845N·m Minimum specific fuel consumption 210g／kw·h 2

Fuel oil: No. 0 or -20 light diesel oi1 Regulator: 　　　　　　　　　　　　　　RFD Fan Diameter:　　　　　　　　　　　　　　　Φ670/Φ700 1.3.2 Transmission system Torque converter Type Dual-turbine type Sta1l torque ratio K=4 Cooling mode Pressure oil circulation cooling Oil pressure of torque converter inlet 0.58MPa Oi1 pressure of torque converter outlet 0.28～0.45MPa Transmission Type Planetary, hydrau1ic power shift Gears Two forwards and one reverse Speed charging pump (gear pump) Revs 2200rpm Rate of flow 120L/min Working pressure 1.1～1.5MPa Differential gear Type Spira1 bevel gear Reduction ratio 5.286:1 Final drive Type Spur planetary gear Reduction ratio 4.4:1 Axles and wheels Drive type All wheels Tire 23.5-25 Tire pressure 0.28～0.3MPa 1.3.3 Brake System Service brake: Air-assisted hydraulic-disk type brake on 4 wheels Diameter of disk Φ＝460mm Diameter of hydraulic cylinder Φ＝75mm Friction lining size(length×width×thickness) 182×72×15mm Parking brake internal-expanding dual-shoe brake Diameter of brake drums 305mm Lining size (length ×width ×thickness) 325×76×6.5mm Air pressure of brake system 0.6～0.8MPa 1.3.4 Steering system Type Articulated frame, full-hydraulic steering Number of steering cylinders-bore ×stroke 2-Φ90×399mm Steering pump CBG2080 Steering gear BZZ1-1000 Working pressure of system 14MPa Turing angle 38 degrees to each direction 1.3.5 Implement Number of arm cylinders-bore ×stroke 2-Φ160×755 3

Number of bucket tilting cylinder- bore ×stroke 1-Φ180×591 Distribution valve Dual-spool type Operation pump CBG3160 Revs 2200rpm Rate of flow 104～352L/min System pressure 16.5MPa Implement arrangement single rocker arm reversing 6-bar linkage 1.3.6 Electrical and instrument system System voltage 24 volt Batteries Model 2-6-Q-195 Lighting system voltage 24 volt Engine starting voltage 24 volt (electric motor) 1.3.7 Oil capacity Fuel tank 278L Hydraulic system 278L Engine crankcase 42L Transmission 45L Axles (differential and planetary system) 40L Front and rear boosters 3.5L 1.3.8 Air conditioning system Heat flow Operation medium Cooling water for diesel engine Cooling flow Operation medium Freon 12(F-12) Cooling capacity 4.2kJ/h System voltage 24 volt CHAPTER 2 OPERATION AND FUNCTION In order to operate the machine safely and reliably, the operation and functions should be thoroughly understood before using the loader. 2.1 Controlling mechanism and instruments The location of controlling mechanism and instruments are shown in fig 2-1, 2-2 and 2-3.

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2.2 Break-in of a new loader During the course of break-in that lasts 60 hours, the operation and maintenance such as followings should be paid enough attention to. 1. The followings must be done after break-in a new loader for 8 hours. (1)Check the fastening of all the bolts and nuts, especially the bolts for cylinder covers, exhaust pipe, front and rear axles, connecting transmission shaft, and nuts for rims. (2)Clean coarse and fine oil filter and fuel oil filter. (3)Check the tightness of the fan belt. (4)Check the proportion and the reserve of the electrolyte in the storage battery, and tighten the terminals of the storage battery. 5

(5)Check the oil quantity of the gear box. (6)Check the seals of hydraulic system, air pressure system, brake system and air conditioning system. (7)Check all the connection of control lever and throttle links. (8)Check all the connection of electric system, the condition of power supply and light illumination and steering signals. 2. Break-in with forward 2nd gear and reverse gear. 3. During the break-in, loading and unloading is not allowed to exceed 70% of the rating load capacity. 4. Pay attention to the lubricating condition of the loader, renew or fill the oil and grease according to requirement. 5. Pay close attention to the temperature for gear box, torque converter, front and rear axles, hubs, brake disk and brake drum. If overheated, find the cause and remedy. 6. Check all the bolts and nuts. 7. During the course of break-in, it is appropriate to shovel loose material. Too abrupt and hasty action is forbidden. 8. The following maintenance should be done after accomplishing the break-in. (1)Check the filter screen of the gear box oil sump, renew the oil. (2)Renew the engine oil. 2.3 Operation of the machine 2.3.1 Points for attention during operation. 1. The diesel oil must be precipitated for at least 72 hours before filling. The name of diesel oil should accord with the requirement. 2. The hydraulic transmission oil filled in the torque converter-transmission and the hydraulic oil filled in hydraulic system should be clean. 3. Periodical maintenance and lubrication should be carried out according to the regulation. 4. The engine should be kept idling until water temperature reaches 55℃ and air pressure reaches 0.35MPa before the loader traveling. 5. The engine should be preheated to above 30 ～40℃with hot water or steam before starting, when the weather temperature is under 5℃. 6. It is unnecessary to stop traveling or to apply service brake for gear shifting. When change the speed from low to high, first release the accelerator pedal, and simultaneously, shift the gear, and then press the accelerator pedal to bring the output shaft of the transmission to rotate with the speed of transmission shaft. Otherwise, press the accelerator pedal directly to shift the gear. 7. It is unnecessary to shift the gearchange into neutral gear position when the service brake applies. 8. The control levers should be shifted into the neutral position when the arm and the bucket are set to the required position. 9. The loader should be stopped before reversing. 10. It is until the temperature of the cooling water has reached 55℃ and the temperature of the engine oil has reaches 45℃ that the loader is permitted to work in fully loaded condition. During operation, the temperature of the cooling water should 6

not exceed 90℃, and the temperature of the engine oil should not exceed 110℃. If the oil temperature exceeds 110℃, the machine should be stopped to cool down. 11. To assure traveling stably when transporting materials, the distance between ground and the underside hinge joint of arm should be 450mm. Lifting the bucket to tiptop is forbidden when transporting materials. 12. The power of the engine such as model X6130G27 will be decrease with the increase in altitude, ambient temperature and relative humidity. Therefore, the user need refer to the power correction table included in the operation manual to acquire the actual power output of the engine under the local condition, so as to ensure the correct use of the loader before operating the machine. The output of model WD615.6AG26 diesel is hardly affected by the environment. 13. In order to protect the parts, the emergency and parking brake should not be applied while traveling except in emergency. 14. In case the engine can not start under trouble or other condition and the loader ought to be towed by another vehicle, it is necessary to affranchise the parking brake firstly. Warning: the loader is deprived of both power steering and brake function at that time. 2.3.2 Checkups and maintenances before and after operation. Checkups before operation 1. Engine, electric appliances and instruments (1) Check water level in the radiator. (2) Check fuel level in the fuel tank. (3) Check engine oil level in the engine oil sump. (4) Check all pipes and other parts for leakage. (5) Check wire connection of the batteries. 2. Chassis (1) Check the hydraulic oil level. (2) Check the hydraulic oil pipes and other parts for leakage. (3) Check the working reliability of the service brake and emergency brake. (4) Check all the control levers to see if they work perfectly and are set to neutral position. (5) Check the air pressure of the tires. 3. After the engine start (1) Observe the readings on all instruments to see if their indications are normal. (2) Check all the lighting installations, turning signal lamps, horn, windshield wiper and brake lamps. (3) Operate the implements mechanisms and check the operating condition. (4) Listen attentively to the sound of the engine at low speed to determine its working condition. (5) Trial run on each gear. 4. Checkups and maintenances after work (everyday) (1) Check fuel level. (2) Check level and cleanness of engine oil. If oil level is too high or the 7

oil become thin, find out the cause and remedy the trouble. (3) Check all the oil, water and air pipelines for leakage. (4) Check the fixation of the transmission, torque converter, hydraulic oil pump, steering gear, front and rare axle, and check whether these components are overheated. (5) Check the tightness of the bolts, studs and nuts of the wheels and transmission draft, and check the fixation of all the pins. (6) Check if the implement mechanism is in good condition. (7) Check the outside appearance and air pressure of the tires. (8) Drain out the cooling water when the temperature of the weather is below 5℃. (9) Fill grease into greasing points. 2.3.3 Start, stop and operate the machine 1. Start After the “checkups before operation” has been carried out and all the parts are in good order, the engine can be started. Before start, set the gearchange and the control levers of implement in their neutral position. Inserting the key to switch on the power, and then press the accelerator pedal slightly, and then turn the starting switch. The starting switch should be turned on for 5 seconds once only (continuous operation of the switch should not exceed 15 seconds). The switch should be released immediately if it is fail to start. Wait for one minute then start again. If the failures are more than 4 times, find out the trouble and remedy it, and then start again. The engine should run at the speed of 600～750 rpm for a while to make the engine warm and check the indications of the instruments especially the engine oil manometer. At the same time, check the engine and the other systems for irregularities. Release the parking brake and shift gear to run after the air pressure reached to 0.3～0.35MPa. 2. Stop Before stopping run the engine at a speed of 800 ～ 1000 rpm for several minutes to enable the parts of engine cool down evenly. The bucket should be lowered on the ground flatwise, then turn off the power and apply the parking brake. All the water drain cocks of the engine should be opened to drain off the water in the cooling system soon after the engine stops in winter. However, there is not need draining off the water if anti-freezers have been added. The storage batteries should be removed and placed in a warm room when the air temperature falls below -30℃ to avoid cold cracking. 3. Operate the implement Preparative for operation (1) The traveling speed for shovel loading materials should be below 1km/h. (2) Clean up the operation ground, fill-in the pits, remove sharp rocks and other obstacles that may damage the tyre or hinder the operation of the loader. 4. Operation modes 8

There are two modes of loading and unloading generally. As shown in fig 2-4(a), the distance between loader and lorry is ten meters, the lorry stops when the loader is working. The working efficiency is higher. Combination operation of the loader and the lorries, as shown in fig 2-4(b), is a fairly appropriate mode for continuous hauling by a lorry team. 5. Shoveling operation (1) Drive the loader towards the stock pile in 1 st gear, with the underside hinge joint of arm 300mm off the ground and the bucket bottom parallel to the ground, as shown in fig 2-5(a). (2) At a distance of one meter in front of the stock pile, lower the arm and let the bottom of the bucket touch the ground and cut into the

stock pile, as shown in fig 2-5(b). (3) Press down the accelerator pedal to force the bucket cutting into the stock pile with full power. If the resistance is too strong, the combined shovel-loading mode should be applied, that is to say, the loading of materials is done by titling up the bucket and raising the arm simultaneously at intervals until the bucket is fully filled. (4) After filling the bucket, raise the arm to the required height, and set the arm control lever to the neutral position, as shown in fig 2-6(c).

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Fig 2-5 Shoveling operation Fig 2-6 Dumping operation 6. Transporting operation The loader is used for hauling under the following condition. (1) For the ground is too soft or the field not leveled, it is too hard to transport with lorry. (2) The hauling distance is less than 500 meters. It is cost waste time to transport with lorry. The transporting speed is determined by the distance and ground condition. In order to keep safety, stability and good visibility during hauling, the bucket should be turned upward to its extreme position and keep the underside hinge joint of arm 450 mm from the ground. 7. Dumping operation When dumping materials into lorries or stock yards, first raise the arm to height so that when the bucket is titled, it will not collide the lorry body or stock pile. Then push forward the bucket control lever to tilt the bucket forward and dump. Bumping of materials should be done slowly so as to minimize the impaction on the lorry. If materials stick on the bucket, control the stick back and forth to shake the bucket, as shown in fig 2-6. After dumping, draw the bucket control lever to its rear extreme position; push the arm control lever to the declining position to prepare for the next cycle of the operation. 8. Bulldozing operation (1) Lay the bucket flat on the ground. (2) Pedal the accelerator and bulldoze forward. When the vehicle is hindered during the bulldozing operation, lift the arm slightly and continue the action. The control lever should not be shifted to either of the two extreme positions but between them while lifting or lowering the arm, as shown in fig 2-7.

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Fig 2-7 Bulldozing operation Fig 2-8 Scraping operation 9. Scraping operation (1) Tilt the bucket to utmost position, and let the bucket blade contact the ground. (2) When the loader is used for scraping hard surface, the arm control lever should be set to the floating position, and for soft surface, it should be shifted to the neutral position. (3) Engage the reverse gear and use the bucket blade to even the ground, as shown in fig 2-8. 10. Towing operation Hitch on a 20-ton trailer for material transportation. (1) Hitch the trailer to the drag pin hard. (2) Shift the implement to the transportation position. (3) Drive the vehicle slowly when starting and stopping. Before driving down a slope, be sure that the brake is ok. When the road is very steep, equip the trailer with brake to ensure safety. 2.4 Lubrication of the machine Proper lubrication will greatly reduce the friction and wear of the machine parts. 1. Points of attention (1) Clean the oilers and the lubrication points. (2) Put the machine in a level position to check the oil level. (3) Add oil to the front and rear axle through fillers at the left and right wheel hubs, until the oil flows out from the oil level plug hole of the axle castings. (4) Add oil to the transmission, until the oil flows out from the oil level petcock. Start the engine and run for 5 minutes, then check the oil level again after filling oil first time. (5) It is forbidden that combines or interchanges different kinds of oil, otherwise, it may cause the ageing of rubber parts and wear on components. 2. Kinds and brands of lubricant are listed in the following table. Type of oil

Name of oil Summer

Winter

Position of use

11

Lithium-base grease

No. 2

No. 1

Roller bearing, sliding bearing and hinged parts

Hydraulic oil

L-HM46

L-HM32

Implement hydraulic system, steering system

Hydraulic transmission oil

Torque converter, transmission

No.8

Engine oil

40CD

5W/30CD

Diesel engine

Fuel oil

No. 0 or No. -10

No. -35

Diesel engine

Gear oil

85W/90

Front and rear axle

Synthetic brake fluid

LG3

Brake system

CHAPTER 3 MAIN ASSEMBLY STRUCTURE AND ITS MAINTENANCE 3.1 Diesel engine LW520 wheel loader may install two types of diesel engine, one is WD615.61AG26, and the other is X6150G27. To operate and maintain the engine, refer to the relevant operation manual. 3.1.1 Cooling system The cooling system is composed of water tank, radiator for cooling the torque converter-transmission oil and an air hood. This unit is fixed on the radiator bracket and rear frame. The water inlet on the top of the radiator is connected to the outlet elbow of thermostat of the engine, and the water outlet at the bottom of the radiator is connected to the oil cooler inlet elbow, and the oil cooler outlet elbow is connected to the water pump of the engine. 3.1.2 Throttle control system The throttle control system consists of accelerator pedal, flexible shaft and so on, and connects with throttle pull plate. The stop screw is used for limiting the maximum opening of the throttle. When assembling, adjust high or short according to condition. 3.1.3 Stopping device The stopping device is a stay wire connecting to the engine stop lever with the wire tube fixed to the casting of the fuel pump. The stopping button locates at the lower right side of the operator’s seat, and when the button is pulled out the engine will stop. 3.1.4 Fuel tank The fuel tank is laid at the lower right side of cab and is fixed to the frame with four bolts. The capacity of the fuel tank is 278 liters. The hydraulic air filter is on the top of the tank and a draining plug is at the bottom. The liquid level meter is placed at the flank of the tank. 3.2 Torque converter & transmission Torque converter & transmission is composed of torque converter and 12

transmission. 3.2.1 Torque converter 1. Feature The LW520 wheel loader is equipped with a dual-turbine hydraulic torque converter between the engine and the transmission for transmitting power with the following advantages. (1) The torque converter can adjust the output and rotate speed automatically that means the loader can change the traveling speed and traction to adapt the various road conditions and operation modes automatically. The torque converter is a stepless transmission, can provide a smooth drive when the vehicle accelerates from start to maximum speed of a gear. The acceleration performance is better than the normal. The torque converter can decrease the speed of the loader and increase the traction without gear shifting automatically while the loader is running across a slope or obstacles. Thus, the vehicle will be able to run and an appropriate speed to overcome the obstacle. When external resistance decreases, the speed of the vehicle will increase automatically. In the same way, when the loader cut into the material pile at high speed, the torque converter can change the speed and traction automatically to assure the cut-in. Having the above superiority, the loader can be operated at a higher average speed and a shorter working circle, which results in higher productivity. (2) Having two turbines, the torque converter can perform the function of an automatic transmission with two gear ratios. For this reason, the configuration of the transmission is more compact with a lower cost. (3) Due to the high torque conversion ratio and the wide high efficiency range, the engine can be operated more effectively to develop traction force and travel speed, which results in good economy. (4) Since power is transmitted by hydraulic oil instead of mechanical connection, the oil absorb the shock or impact between the input and output shafts to protect the diesel engine and the transmission. Accordingly, the longevity of the loader is protracted and the cost and the workload of maintenance are reduced. And the engine cannot be stalled even by a sudden increase of externa1 load, thus the oil pumps wi1l work continuously and this ensures safe and reliable operation of the vehic1e. (5) Due to above features, the driver’s labor intensity is greatly lessened, and the vehicle is more comfortable to operate. 2. Operation principle As shown in fig 3.2-1, the torque converter consists of four basic parts: the impeller B, the turbines T1 and T2, and stator D. The cavity formed by these parts is filled with oil. Impeller B is driven directly by the engine, turns at engine speed n B and converts the engine power into hydro-dynamic energy to force the oil in the cavity flow from impeller B to the turbines T1 and T2 where its dynamic energy is absorbed as torque delivered to the overdrive clutch via gears Z 1 and Z3; and the oil pressure causes turbines T1 and T2 to rotate at speed nT1 and nT2 respectively. The 13

circulation of oil in the converter is shown by arrow in the fig. The turbine T 2 then redirects the oil back toward the impeller B. Stator D is the reaction member and is interposed between turbine T2 and impeller B to change the direction of oil flow so that it enters the impeller in the same direction as the impeller is rotating. Due to the design of the wheels blades, the oil flows that go in and out each wheel have different track and direction respectively. Because of nB is equal the engine speed and nT1 and nT2 is changing according to external load, the speed and direction of the oil flow are changing continually. So the torque coming from the impeller and the torque directing by the stator are both changing. As a result, the sum of the torque (positive) coming from impeller and the torque (positive or negative) coming from stator which is acquired by the turbines is changing. When the torque that coming from stator is positive, the torque of output shaft increases and vice versa. Thus the torque transferred through the converter is changed, and the stator is necessary for the transformation of torque. The flow of oil in turbine T2 moves from the periphery toward the hub. The torque developed by the fluid force is delivered through gear pair Z 3 and Z4 to the output shaft of the torque converter. Turbine T2 transmits the engine power to the output shaft principally under light load and high speed condition. The oil passes the blades of turbine T1 in axial direction. Turbine T1 transmits torque when the load demand is his and vehicle speed is lower. Under such conditions, the overdrive clutch locks gear Z2 to gear Z4 by the wedge action of the rollers, so that the torque from turbine T1 can be transferred to the output shaft and combines with that of turbine T 2. In the overdrive clutch, as shown in fig 3.2-1, the roller under the action of the spring is held between the peripheries of the cam, which is connected to gear Z 1, and the inside of the hub of gear Z2. When the vehicle is at high speed and the load demand is low, gear Z4 together with the cam runs faster than gear Z2, the roller rotates in direction “A” and gear Z2 spins freely. Thus, the torque is delivered by turbine T 2 to the output shaft. As the load demand increases and gear Z 4 is rotating slower than gear Z2, the roller rotates in direction “B” and the overdrive clutch locks gears Z 2 and Z4 together by the wedge action of rollers. Thus, the torque delivered by each turbine is combined with the other, and both turbines deliver the combined torque to the output shaft. The overdrive clutch is engaged or disengaged automatically according to the variation of vehicle speed and load demand.

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Fig 3.2-1 Operation principle of torque converter 1. Diesel engine 2. Flywheel 3. Cam Ring gear 5. Spring 6. Roller 7. Overdrive clutch 8. Output draft 9. Working cavity 10. Casing 3. Structure The left half and the K and H views of fig 3.2-2 show the structure of the torque converter. The converter housing 13 is connected at the left end to the engine flywheel housing and at the right end to the housing 4, and on the contact surfaces of both ends are placed gaskets 21 and 9 respectively. The pump impeller 16 and pump cover 25 are connected with bolts. The flexible plates 28 are bolted to the engine flywheel 22 and the pump cover, so that the pump impeller is driven at engine speed. The turbine set is composed of first turbine 18 and second turbine l9. The first turbine is fixed to the turbine cover 23 by roll-pins l7 and riveted to the hub 26. The two turbines are splined respectively to the first turbine drive gear 5 and the second turbine drive gear 8, which are co-axial and rotating independently. The sleeve 10 is fixed to the converter housing 13 and supports the pump impeller on bearing. The stator 27 and spacer 15 are splined to the sleeve and constrained by a circlip put in the groove at the end of the sleeve. Gear l4 is fixed to the pump impeller l6. This gear drives the oil pump, and when tows starting, wheel torque is transmitted to the engine through this gear. A seal ring 12 is placed between gear l4 and sleeve l0, and some oil will leak out from the converter during operation, but oil pressure will not reduce. The seal rings 7 and l1 are used in the same way as seal ring l2. Brass ring 6 is a spacer ring placed between gear 5 and 8 to let them rotate at different speeds. Spring 36 in the overdrive clutch, as seen in the H view of the drawing, are installed between flanges of the cover plate 37 and lugs of the roller cage 38. Under the action of the springs, the rollers 35 are in contact with the inside surface of the hub of gear 40 and the face of cam 39. Gear 40 and cam 39 rotate in same direction. When the former is faster than the latter, the clutch engages and when the latter is faster than the former, the clutch is released. 15

Pressure regulation valve 32 controls the inlet oil pressure of the torque converter, and the back-pressure regulation valve 33 controls the pressure of the lubricating oil. 4. Interior oil passage The pressure oil from the charging pump 1 enters the torque converter from port “A” (shown in K view) and flows through port “D” and channel “E”, passing through the converter pump hub bearing, around the spacer ring 15, and then enters the cavity of the converter, to fill it continually. Excess oil from the space “G” flows between sleeve 10 and second turbine drive gear shaft, as indicated by letter “F”, and leaves the converter housing 13 through port “B” as shown in the K view. 3.2.2 Transmission 1. General description The planetary type hydraulic-operated transmission used in the ZL50F can provide two forward speeds and one reverse speed. Its advantages are simplicity,

Fig 3.2-2 Torque Converter-Transmission l. Charging pump 2. Gasket 3. Oil pump driven gear shaft 4. Housing 5. 1st turbine drive gear 6. brass ring 7. Seal ring 8.2nd turbine drive gear 9. Gasket l0. Sleeve ll. Seal ring l2. Seal ring l3. Converter housing 14. Oil pump drive gear l6. Pump impeller 17. Roll pins 16

l8. 1st turbine l9. 2nd turbine 20. Locking washer 21. Paper gasket 22. flywheel 23.Turbine cover 24. Rivets 25. Pump cover 26. Turbine hub 27.stator 28. Flexible plates 29. Oil temperature gauge connection 30. Pipe connection 3l. plug 32. Pressure regulator valve 33. Back-pressure regulation valve 34. pipe connection 35. Rollers 36. Springs 37. Cover plate 38. Roller cage 39. Cam 40. 1st turbine driven gear 41.2nd turbine driven gear shaft 42. Bearing 43.Bolt 44.Sun gear 45. Reverse planet pinions 46. Reverse planet carrier 47.1st gear planet pinions 48. Reverse ring gear 49. Front and rear axle connection pull rod 50. Front and rear axle connection shifting fork 51. Rear output shaft 52. Sliding sleeve 53. Output shaft gear 54. Front output shaft 55. Middle cover 58. Cylindrical pin 57.lntermediate shaft output gear 58. 1st-gear planet pinion spindles 59. Disk spring 60. End cover 6l. Ball bearing 31l 62. Direct-gear shaft 64. Direct-gear cylinder 65. Direct-gear piston 67. Bolts 68. Direct-gear friction clutch 69. Direct-gear drive plate 70. Direct-gear connecting flange 71. 1st=gear planet carrier 72. 1st-gear cylinder 73. 1st-gear piston 74. 1st-gear ring gear 75. 1st-gear friction clutch 76. Spring 77. Springs guide pins 78. Reverse gear friction clutch 79. Reverse gear piston 80. Duplex pump 81. Steering oil pump

compactness, high rigidity, high driving efficiency, simple and reliable controlling, and longer service life. The transmission is mainly composed of the housing, overdrive clutch, planetary assemblies, friction clutches and pistons, changing oil pump hydraulic control valves, oil strainer, shafts and gears. The function of the transmission is to transmit the engine torque, and to change the driving direction and speed of the vehicle. The charging pump sucks the oil from transmission casing through filter and feeds it into control valve; operator can use the control lever to feed pressure oil into selected chamber then to shift the transmission according to his demand. When road condition is severe, use shifting fork and sleeve, to connect rear output shaft to front output shaft to implement four-wheel drive. 2. Structure and operation principle (1)The planetary assemblies are shown in fig 3.2-2. There are two planetary assemblies in this transmission for the reverse gear and the 1st gear. The p1anetary gear set is mainly composed of the planet carrier, planet pinions, planet spindles, internal ring gear and sun gear. The planet pinions are carried on the planet carrier, and are in mesh both with the sun gear and the ring gear. The driving plates of the 1st-gear friction clutch 75 are splined to the 1st-gear ring gear 74, the driving plates of the reverse gear clutch 78 are splined to the reverse planet carrier 48. When the control valve is shifted to 1st gear, the 1stgear ring gear 74 is locked by the 1st-gear clutch 75. The sun gear 44 drives the planet pinions 47 to rotate round their own axes, causing the pinions together with the 1st-gear planet carrier 71 to revolve about the axis of sun gear 44. Therefore, power is transmitted through the planet carrier to the output shaft. When the control valve is shifted to the reverse gear, the reverse planet carrier 46 is locked and there is no planetary motion. The sun gear 44 drives the reverse planet pinions 45 , which in turn drives the reverse ring gear 48 to rotate in opposite direction to that of the sun gear , and the power is output from the gear set by the reverse ring gear 48. In the reverse planetary assembly, the friction clutch brakes the reverse carrier 46, and the power is output through the reverse ring gear 48. But in the 1st17

gear, the friction clutch brakes the 1st-gear ring gear, and the power is output through the 1st-gear planet carrier 71. Therefore, the direction of torque that output through the two assemblies is opposite. It must point out that when reverse, 1st-gear friction plate clutch is released, the planet gear and ring gear is in idle and power is only transmitted by the carrier 71. (2) The transmission control valve, as shown in fig 3.2-3, includes the pressure regulator valve, cut-off valve, distributing valve, compensating valve and pump body.

Fig 3.2-3 Transmission control valve 1. Pressure regulating valve rod 2. Spring 3. Spring 4. Pressure regulating ring 5. Sliding piston 6. Gasket 7. Spring 8. Cut-off valve spool 9. Plunger 10. Air valve rod 11. Air valve body 12. Distributing valve 13. Balls 14. Spring 15. One-way throttle valve 16. Spring 17. Leather cup a. Reverse gear b. Neutral gear c. 1st-gear d. 2nd-gear

Principle of the control valve ①Pressure regulator valve: As shown in fig 3.2-3, the regulator valve 1 is held in balanced position by spring 2 and the other end of the spring acts on the sliding piston 5. The piston compresses spring 3 also. Cavity C is the oil line inlet of the control valve, and it connects with cavity A through an orifice of rod 1. Cavity B is interlinked with the oil tank and cavity D is interlinked with the torque converter. After the engine is started, oil from charging pump flows into the pressure regulator valve 1 through cavity C, and then the oil channel F, the cut-off valve 8 and the oil channel T to the distributing valve 12. At the same time oil from cavity C passes through the orifice of valve rod 1 to cavity A and pushes valve 1 to the right. Thus, the cavity D is opened, a portion of the oil from the charging pump flows to the torque converter. The oil in channel T also passes through channel P into the cavity E of the compensating valve, and the oil pressure acts against the piston 5 pushing it to the left. When the spring force balances the oil pressure, the pressure is regulated. When the system oil pressure rises and exceeds the specified value, piston 5 18

continually move to the left and is restricted by pressure regulating ring 4. The oil pressure in cavity A is increased, the oil pushes the regulator valve to the right, When port B is opened, a portion of oil from cavity C returns to the oil tank and the oil pressure will decrease so that the system pressure maintains at the specified range. And then, the regulator valve 1 move left again and port B is closed. Therefore, the pressure regulator valve is able to regulate the pressure and also act as a safety valve. ②Distributing valve: As shown in fig 3.2-3, the distributing va1ve 12 is held in position by spring 14 and detent balls 13. The movement of the distributing valve can engage the 1st-gear, 2nd-gear and reverse gear. The port M, L and J are connected to the cylinders of the 1st, 2nd and reverse gear respectively, and port N, K and H are separately connected to oil tank. Cavities U, V and W are interlinked with oil channel T. When the distributing valve is shifted to the 1st-gear position, pressure oil flows from cavity V to port M, and through which oil is directed to the 1stgear cylinder and its pressure applies the clutch. At this time, the inlet port L and J are blocked. The gear position and the corresponding oil inlets and outlets are list in the following table: Gear position Oil inlet Oil outlet st 1 -gear M N nd 2 -gear L K Reverse gear J H When the distributing valve is shifted to the 2nd-gear, oil in cavity U flows to port L and actuates the 2nd-gear clutch. At this time, ports M and J are blocked When the distributing valve is shifted to the reverse gear, oil from cavity W flows to port J and its pressure applies the reverse gear c1utch. At this time, the oil inlets M and L are blocked. ③ The sliding piston: As shown in fig 3.2-3, the sliding piston provides more rapid and smoother engagement of the friction clutch. At the right side of this piston, cavity E of the valve is connected to channel T through orifice Y and also the one-way valve 15, When the distributing valve is shifted to one of the clutch positions, oil from channel T flows to the connected clutch cylinder. It is obvious that there is a pressure drop in channel T, and therefore, not only the oil from the pressure regulating valve flows through channel T into the cylinder, but also the pressure oil from cavity E supplies to that cylinder through the one-way valve 15 and channels P and T in sequence. Because of the combined oil flow, the clutch cylinder is filled quickly and oil pressure in the cylinder and channel T is increased rapidly. Thus, the compensation piston serves to accelerate the engaging of the clutch. If the cylinder is continually to be filled with oi1, the c1utch will be filled with oil and suddenly engaged and it wil1 result in shock. However, as the oil from cavity E flows to the cylinder, the pressure at E is reduced so that both piston 5 and the pressure regulator 19

valve move to the right. When the clutch cylinder is filled sufficiently with oil, pressure in channel T again rises, causing the oil to be fed back to “E” through channel P and past orifice Y, at this time. The one-way valve 15 is blocked. As a result, oil pressure at the passages increase more slowly, and the engaging of the clutch is smoother, After the engagement of the clutch, the pressure at channel T and the pressure at cavity E are then balanced, and the latter is filled again with pressure oil for the next gear shifting process. 3. Power path in the transmission (refer to fig 3.2-2) 2nd-gear or direct gear: When the distributing valve of the transmission control valve is shifted to the 2nd-gear position, pressure oil from the control valve is directed to the 2nd gear cylinder 64 via the oil inlet at housing 4 pushing the direct-gear piston 65 to the left and engaging the clutch plates 68. Since the direct-gear drive plate 69, direct gear cylinder 64 and intermediate shaft output gear 57 are connected together with bolts 67 and the pins 56 are fixed onto the direct-gear drive plate 69. Therefore, the power transmitted from the 2nd turbine drive gear shaft 41 is transferred through sun gear 44, direct-gear shaft 62, via clutch 68 and pins 56 to the direct-gear drive plate 69. From here, power is then transmitted through gear 57 to the front output shaft 54 to achieve a high speed forward drive. The path is: 2nd turbine drive gear shaft 41 →Sun gear 44 → Direct-gear shaft 62 → Direct-gear friction clutch 68 → Direct-gear drive plate 69 → Bolt 67 → Direct-gear cylinder 64 → Intermediate shaft output gear 57 → Output shaft gear 53 → Front output shaft 54 1st-gear: When the distributing valve of the control valve is set to the 1st-gear, pressure oil flows from the control valve through oil port at housing 4 into cylinder 72 of the 1st-gear, and pushed the 1st-gear piston 73 to the left, to engage the 1 stgear clutch 75. As this clutch now holds the ring gear 74 stationary, the power path is through the sun gear 44, 1 st-gear planet carrier 70 which is bolted to the carrier 71. Power is thus transmitted to the direct-gear drive plate 69 since flange 70 and plate 69 are connected by spline. The rotating direction of the direct gear is the same as the 2nd-gear. The path is: 2nd turbine drive gear shaft 41 → Sun gear 44 → 1st-gear planet pinions 47 → 1st-gear planet carrier 71 → Direct-gear connecting flange 70 → Direct-gear drive plate 69 → Bolt 67 →Direct-gear cylinder 64 → Intermediate shaft output gear 57 → Output shaft gear 53 → Front output shaft 54 Reverse gear: When the distributing valve of the transmission control level is set to the reverse gear position, the pressure oil from the control valve flow, through the reverse oil port at housing 4 to the reverse gear cylinder pushing the reverse gear piston 79 to the right, engaging the reverse gear clutch 78. The engaged clutch locks the reverse planet carrier 46 so that sun gear 44 drives the reverse gear pinions 45 which in turn, drives the reverse ring gear 48 which is attached to the carrier 71 of the 1 st-gear planetary assembly, power from the reverse ting gear is transmitted to the 1st-gear planet carrier. The direction of rotation of the 1st-gear planet carrier is reversed, thus, 20

backward drive is achieved. The path is: 2nd turbine drive gear shaft 41 → Sun gear 44 → Reverse planet pinions 45 → Reverse ring gear 48 →1st-gear planet carrier 71 →Direct-gear connecting flange 70 → Direct-gear drive plate 69 → Bolt 67 →Direct-gear cylinder 64 → Intermediate shaft output gear 57 → Output shaft gear 53 → Front output shaft 54 3.2.3 Torque converter-transmission hydraulic system The heat that generates during operation of the torque converter transmission is carried by force circulating oil and dissipated at the oil cooler. The hydraulic system is shown in fig 3.2-4. The charging pump 4 draws the oil from oil sump 1 through strainer 2 and flexible hose 3, and pumps it to oil filter 6 through a hole being dril1ed in the sump

Fig 3.2-4 Torque converter-transmission hydraulic system 1. Oil sump 2. Oil strainer 3. Hose 4. Charging pump 5. Hose 6. Oil filter 7. Hose 8. Pressure regulator valve 9. Clutch cut-off valve 10. Distributing valve 11. Direct-gear cylinder 12. 1st-gear cylinder 13. Reverse gear cylinder 14. Air valve 15. One-way valve 16. Compensating piston 17. Oil pipe 18. Pressure regulating valve 19. torque converter 20. Hose 21. Oil cooler 22. Hose 23. Back-pressure regulating valve 24. Overdrive clutch a. Air inlet housing and flexible hose 5, then to the hose 7 and sends it to the transmission control valve. Oil filter 6 incorporates a by-pass valve which opens at 0.08-0.12MPa. The bypass valve opens to allow the oil to by pass the filter when the filter element is clogged and resistance exceeds the normal pressure range. The pressure oil separates into two routes when goes out the control valve. Along one route, oil f1ows to the pressure regulator valve 8 (1.1-1.5MPa), clutch out-off valve 9 and the distributing valve 10. According to the various positions of the distributing valve 10, oil flows to 21

the 1st, 2nd or reverse gear cylinder through the oil passages D, B or A respectively. Structure and operating principles of the transmission control valve are detailed in the section “Structure and operating principles of Transmission” in this manual. Along the other route, the oil flows to torque converter l9 through pipe 17 in the housing wall, and then flows to the oil cooler 21 through flexible hose 20 and then returns to the transmission through flexible hose 22. The coo1ed oil then flow back to port J, shown in fig. 3.2-3, on the torque converter housing 13 to lubricate the overdrive clutch and the planetary assemblies and then returns to sump 1. Pressure regu1ator valve 18 controls the torque converter inlet oil pressure at 0.56MPa, outlet pressure at 0.28-0.45MPa. Back-pressure regulator valve 23 controls the lubrication oil pressure at 0.1-0.2Mpa, when this value exceeded the valve will open to release the pressure. 3.3 Drive axles 3.3.1 General description There are one front axle and one rear axle in a wheel loader. The front and the rear are same except that the spiral angles of their drive spiral bevel gears have opposite direction: the front one is the left-hand, while the other is right-hand. To increase the traction force and traveling performance, LW520 equips with two axles driving. 3.3.2 Structure and principle The axle consists of the axle housing, drive gear and pinion, differential, shafts, hub reduction gear set, and wheel assembly, as shown in fig 3.3-1. The housing of axle, supporting all the loads of the vehicle, is fixed on the frame. At the same time, the housing of axle is the setting foundation of drive gear and pinion, differential, the axle shaft and hub reduction gear set. The main drive, as a speed reducer transmitting the torque and changing the direction of motion, consists of one single pair of spiral bevel gears. The differential is composed of two differential side gears, differential pinion cross, four planetary common bevel gears, left and right halves of the differential casing. The differential permits left and right wheels to rotate at different speed, and transmits power from the drive gear to the axle draft. The axle drafts are full floating, and transmit power to the final drives. The final drive is sun-and-planet gear. The ring gear is fixed to the wheel supporting shaft at the end of the axle housing, and the planet carrier is connected to the wheel hub. Motion of the ax1e shaft is transmitted to the planetary set through the sun gear, which is mounted on the end of the shaft. The function of this mechanism is to reduce the rotate speed and increase the output torque, to fit the requirement of working speed.

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Fig 3.1-1 Drive axle 1. Main drive 2. Bolt 3. Vent pipe 4. Stud 5. Axle shaft 6. Disk brake 7. Oil seal 8. Wheel supporting shaft 9. circlip 10. Bearing 11. Dustproof hood 12. Brake disk 13. Wheel hub 14. Tyre 15. Rim ring 16. Check ring 17. Rim nuts 18. planet carrier 19. Ring gear 20. Check ring 21. Planet pinion 22. Shim 23. Planet pinion shaft 24. Ball 25. Needle roller 26. Cover 27. Circlip 28. Sun gear 29. Gasket 30. Round nut 31. Bearing 32. Bolt 33. Plug 34. Rim Tyre and rim assembly is the main travel part. Model 23.5-25 tyre is used on the loader. It is of low pressure and wide base type with lower ground pressure, suitable for cross-country traveling and has good adhesion. 3.4 Transmission shaft The transmission shaft transmits the power from the transmission to the drive axles. The front transmission draft is a reformed version of STYLE Truck transmission draft and the rear one is a reformed version of DONFENG Truck transmission draft. 3.5 Brake system 3.5.1 General description The brake system of LW520 loader consists of service brake system and emergency/parking brake system. 1. Service brake system. This system is used to control general travel speed and break the vehicle with air-hydraulic clamp brakes in all four wheels. It provides the advantage of smooth braking safety reliability, compacted structure, easy maintenance and the better recuperative character under wet condition. 2. Emergency/parking brake system This system is used for parking. Sometimes, this system and the service system may be use together to deal with the emergency. 3.5.2 Structure and principle The principle of the brake system is shown in fig 3.5.1.

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(1) The compressed air produced by the air compressor 1 first flows into automatic drainage and pressure regulator 2, then into the air tank 3. When braking, the compressed air flows into air-hydraulic booster 7 through foot brake valve 6 and presses brake liquid. The piston and plate are pushed toward the brake disk to brake the disk by the brake fluid. (2) Emergency/parking brake system should be used when the service brake system is out of order or when the loader parks. 3.5.3 Principle of main components 1. Automatic drainage and pressure regulator is shown in fig 3.5-2. The function of this valve is to separate oil, water and other impurity in compressed air coming from the air compressor. The valve will cool and limit the pressure of compressed air to protect the air circuit as a safety valve and can be used to inflate the tyre also.

Fig 3.5-2 Automatic drainage and pressure regulator Principle: The compressed air from air compressor flows into chamber C through inlet B, then pass through strainer a and check valve f to the outlet D and charges into air tank. When the pressure of tank reaches a certain value, the compressed air in chamber E pushes diaphragm d to open inlet valve e, the air then flows into chamber F, pushes down the piston f and opens the 24

lower vent valve g to exhaust the compressed air in chamber C together with condensed water and impurity in the lower portion of chamber C, through vent port G into atmosphere. If the pressure is reduced in air tank, the inlet valve e and vent valve g are closed in turn under the operation of spring. The pressure regulator continues to charge air into tank. When inflating tyres, unscrew the cap P and connect an air hose. Piston rod h is pressed by the hose and blocks the path of outlet and compressed air flows entirely into the tyre through the center hole in piston rod. If the inflating pressure exceeds 0.98MPa, the relief valve R will open and air will exhaust from hole m. After the loader has been working for 1000 hours, maintenance of the valve is necessary. Dismantle the nether half, clean the screen a, and then lubricates the moving surface between piston f and upper portion with proper amount of grease after cleaning. The entire maintenance is necessary after the loader has been working for 5000 hours. Warnings: The pressure control valve is adjusted properly before delivery, further adjustment is forbidden. 2. Foot brake valve is shown in fig 3.5-3.

Fig 3.5-3 Foot brake valve 1. Air tank 2. Drain valve 3. Front brake chamber 4. Rear brake chamber 5. Push rod 6. Balancing rod 7. Balancing piston 8. vent 9. inlet valve 10. Balancing spring The function of foot brake valve is to switch of and cut off the compressed air circuit to the booster. Principle: When braking, press down push rod 5 which in turn, via balance rod 6 pushes down both balancing piston 7 of the two chambers to close vent valves 8 and open inlet valve 9. The compressed air from air tank is input chamber V through valve 9 and flows into front and rear brake chamber through both vent port respectively. The air pressure of chamber V is to balance the force that balancing pod exerts the spring a. In balanced condition the vent valve is closed, the air pressure at vent port corresponds with push rod force, change the push rod pressure, then the new balanced air pressure can be obtained at vent port. The value of output air pressure P 2 changes along with the push rod force F. 25

When releasing brake, the operation process is opposite to braking process. The compressed air in both vent port is exhausted into atmosphere through vent valve 8 and bleeding port D respectively. Warnings: The rubber dustproof hood on the top of brake valve must be kept in good condition and the inner chamber of brake valve must be cleaned periodically. Apply proper amount of 1ight lubricant on the surface of piston to maintain its smooth motion. The rubber drumhead should be kept complete. 3. Air-hydraulic booster is shown in fig 3.5-4.

Fig 3.5-4 Air-hydraulic booster 1. Screw joint 2. Piston 3. Y-shaped seal ring 4. Felt ring 5. Spring 6. Lock ring 7. Thrust washer 8. Leather ring 9. End cover 10. Filler plug 11. Packing 12. Strainer 13. piston 14. Leather cup 15. Spring 16. Return oil valve A. Return oil port B. Compensating port The function of air-hydraulic booster is to convert the air pressure into hydraulic pressure and enlarge the pressure. The booster consists of air cylinder and hydraulic master cylinder. When air pressure reaches 0.680.7MPa, the hydraulic pressure is 10MPa. Principle: When brake is applied, the compressed air pushes piston 2 to overcome the resistance of spring 5 and move to the right. The piston 2 and push rod push the piston 13 to right, so a high pressure generates in the hydraulic master cylinder. The pressure oil opens the small flapper on the return valve 16 and enters brake cylinder to activate the brake. When the brake is released, the compressed air turns back to the air tank via the screw joint 1. The piston 2 and 13 return to theirs original position under the action of spring. The brake liquid in the brake turns back to the booster through the return oil valve 16. If the brake liquid is too much, it will flow to the oil-holder via the compensating port B. If the pedal is released too fast, the brake liquid can not return back to the hydraulic master cylinder in time, there will be a meiobar in the cylinder. The brake liquid in the oil-holder will compensate the cylinder via return oil port A and six small holes on the head of the piston 13 around the leather cup 14 under atmospheric pressure. Thus, the brake will be more powerful when applying second time. 26

In order to keep air from immerging the system via the screw joint or leather cup, return oil valve 16 has a small valve which can keep the pressure of the hydraulic path when it was closed. 4. Clamp-disk brakeis shown in fig 3.5-5.

Fig 3.5-5 Clamp-disk brake 1. Inner clamp 2. O-ring 3. Dust ring 4. Friction plate 5. Piston 6. Outer clamp 7. Brake disk 8. Pipe connection 9. Air bleeder The function of clamp-disk brake is to create friction, which brakes the wheels, between the plates and the brake disk. Principle: When brake is applied, pressure oil from the booster flows into clamp and pushes piston 5 carrying friction plates 4 which press on brake disk. Since the clamp is fixed on the wheel hub, and brake disk rotates with the hub, the friction force between friction plates and brake disk will stop the wheel rotation. When the brake is released, the piston 5 returns to its original position under the action of seal ring 2. When friction plates are worn, the gap between plates and brake disk is increased; the force of oil overcomes the friction force between piston and seal ring and moves the piston relatively, so that the seal ring deformation is resiled to compensate the gap. The friction plate should be replaced when worn down to the bottom of the longitudinal grooves. 3.6 Hydraulic system The main components of the hydraulic system of implement include the operation pump, distributing valve, arm cylinders, bucket tilting cylinder, oil tank and oil pipe, etc. The principle of the hydraulic system of implement is shown in fig 3.61.

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Fig 3.6-1 Principle diagram of implement hydraulic system 1. Arm cylinder 2. Bucket tilting cylinder 3. Distributing valve 4. Operation pump 5. Coarse filter 6. Oil tank 7. Fine filter Distributing valve The distributing valve, as shown in fig 3.6-2, is a single-piece two-spool valve, consisting of a bucket directional control valve, an arm directional control valve and a safety valve. Series-parallel internal passages are employed between the two directional control valves. The function of the valve is to control the moving direction of the tilting cylinder and the arm cylinder by changing the flow direction of the hydraulic fluid, or to set the bucket or the arm to a certain position to meet the needs of various operational movements. The bucket tilting valve is a three-position valve and is able to control the three movements of forward tilting, back tilting and hold. The arm directional control valve is a four-position valve and is able to control the raising, hold, lowering and floating movements of the arms. The spring 4l in the arm return valve 42 presses the steel balls 40 towards both ends against the V-shaped groove on the inside wall of detent sleeve 44. Therefore, it is possible to detain the arm valve stem in any one of the four working positions. The safety valve controls the pressure of the system and when the pressure exceeds l7MPa, it opens to allow the oil to return to the tank, protecting the system from damage. The side opening P of the distributing valve connecting to the operation pump is the oil inlet. The upper opening (as shown in S-S view in fig 3.6-2) connecting to the oil tank is the oil return port. Cavities A and B are respectively connected to the front and rear chambers of the bucket tilting cylinder and cavities C and D are relatively connected to the upper and lower chambers of the arm cylinders. The seven oil grooves in the valve casing 14 are symmetrically arranged side to side. The load relieve oil channel at the neutral position is of a three groove construction, so that

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Fig 3.6-2 Distributing valve 1. Cotter pin 2. Waster 3. Round shouldered pin 4. O-ring 5. Spring seat 7. Retainer ring 9. YX type seal ring 10. Check valve 11. Bolt 12. Nut 13. Washer 14. Valve casing 15. Bucket tilting spool 16. Arm spool 17. main valve sleeve 18. Main valve spool 19. Main valve spring 20. Pilot valve seat 21. O-ring 22. Pilot valve 23. Spring set 24. O-ring 25. Pilot valve spring 26. Pilot valve case 27. Pressure adjusting screw 28. Nut 29. Washer 30. Locknut 31. Spring seat 32. Return spring 33. Spring seat 34. Positioning seat 35. Tilting return sleeve 36. Seal 37. Shim 38. Washer 39. Detent spring 40. Steel ball 41. Spring 42. Arm return sleeve 43. Spring seat 44. Detent seat 45. Bolt 46. Washer 47. O-ring 48. Screw plug 49. Screw plug 50. O-ring 51. Bolt 52. O-ring 53. Screw plug 56. Sleeve 57. Dustproof ring

hydraulic motivity may be eliminated when changing direction and the oi1 return resistance is reduced. Two check valves 10 are mounted on the two ends of the bucket ti1ting slide valve, and are respectively pressed tightly against the valve seats by spring 39. There is another check valve mounted on the left end of the arm slide valve l6 and pressed tightly against the valve seat by a spring. The use of the check valve is to prevent the pressure oil to flow back to the tank when changing direction, therefore, overcoming the phenomenon of “nodding” of the working mechanism during operation. Moreover, the back pressure produced by the returning oil will also stabilize the work of the system. (1) The working principle of distributing valve 29

1 Neutral position ( blocked position) The oil circuit on both the bucket tilting and the arm cylinders are locked and the latter stop at a certain position. The oil coming from the pump now flows into the tank through inlet P, then Ⅱ, Ⅲ, Ⅳ and Ⅴ to the return opening and then through the return piping to the oil tank. The safety valves are shut and the system makes idle circulations. 2 Bucket back tilting (up turning) Move the bucket tilting slide valve to the right. The pressure oil flows into the valve bore from oil channel I in the valve case, pushes open the check valve, and then flows into oil channel B, which is connected to the rear chamber of the bucket tilting cylinder. The oil then flows through a pipeline to the rear chamber of the bucket tilting cylinder, allowing the piston rod to extend and tilting the bucket backwards. The return oil coming from the front chamber of the cylinder enters the valve bore through channel A to open the check valve, and flows into channel W to return to the oil tank. 3 Bucket forward tilting (down turning) Move the bucket slide valve to the left. The pressure oi1 flows from the valve case into oil channel Ⅲ and then the valve bore, and pushes open the check valve. The oil from the valve bore enters oil channel A which connects to the front chamber of the bucket tilting cylinder, drawing back the piston rod to tilt the bucket forward. The check valve is opened by the returning oil from the cylinder rear chamber and oil enters the valve bore from channe1 B which connects to the cylinder rear chamber and flows into the oil return to channel I then turn back to the oil tank. 4 Arm raising Move the arm slide valve to the right. The pressure oil goes through channel Ⅳ in the valve casing to the valve bore, opens the check valve, then enters channel D which connects to the arm cylinder lower chamber and flows into it to extend the piston rod and raise the arms. The returning oil from the arm cylinder upper chamber returns to channel C in the distributing valve casing, flows through the passage via the center of the valve spool to the valve bore and then goes back to the tank through channel Ⅳ. 5 Arm lowering Move the arm slide valve to the left. The pressure oil enters into the valve bore and the center passage of the valve spool through the upper channel Ⅴ then flows out and reaches channel C which connects to the upper chamber of the arm cylinder. Thus the piston draw back and the arms lower down. The oil in the cylinder lower chamber passes through the pipeline and returns to channel D in the distributing valve casing. After entering the valve bore and opening the check valve, the oil flows into channel Ⅰ through the valve bore and then returns to the tank. 6 Arm floating 30

When the arm slide valve is in floating position, the oil from pump flows back to the oil tank through the neutral unloading groove and channel Ⅵ. The upper and lower chambers of the arm cylinders connects with the oil return channel through oil channels C and D respectively, and then the holes on the valve spool. An unpressurized idle circulation is formed in the system. The cylinders are in the free floating state caused by the action of the implement weight and the ground. (2) Safety valve The safety valve which regulates the system pressure is incorporated of the distributing valve as shown in fig 3.6-2. It is a pilot-operated valve consisting of two parts: the main valve and the pilot valve. The opening and closing of the main valve is controlled by the pilot valve. When the pressure of the system is below the compression of spring 25, and not enough to open the pilot valve 22, the conic valve is closed and no oil flows through the circular damping orifice a at the center of main valve spool l8, so that the pressures at both sides of the spool 18 are equal. Under the action of the main valve spring 19 and the differential pressure causing by the differential area between the left side and the right side of spool 18, the spool keeps standing at the right position. So the bypass channel between pressure cavity P and return oil cavity Ⅰin the valve casing is closed. When the system pressure increases enough to overcome the force of the spring and open the pilot valve 22, a small portion of pressure oil flows to the return oil cavity Ⅰ through the damping orifice a. Due to the action of the damping orifice, a differential pressure creates, and the oil pressure on the right side of the spool is lower than that on the left. When the force produced by this differential pressure exceeds the force of spring 19, it pushes the spool to the left to open the valve, and a large amount of pressure oil flows back to the oil tank through the by-pass channel H, so that a protection against overload is obtained. The working pressure of the system at this time should be 17MPa. When the system pressure is below 17MPa, the pilot valve closes to stop oil flowing through the orifice a and the differential pressure disappears. The spool returns to its original position and closes the oil return opening. The system pressure achieves by adjusting the adjusting screw 27 which changes the compression of spring 26 with. Double-action safety valve for front and rear chambers The double-action safety valves are assemblies of a differential type safety valve and a check valve, and its structure is shown in fig 3.6-3 and fig 3.6-4. The valves are bolted on the distributing valve. Their ports A and C connect to distributing channels for front and rear chamber of bucket tilting cylinder respectively. Ports B and D connect to oil return channels. They provide overload protection and oil replenishment effects on the front and rear chambers of the bucket tilting cylinder. The safety valves are set at 19.5MPa for the rear chamber and l0MPa for the front chamber. When the pressure in the front chamber of the bucket tilting cylinder exceeds 10MPa or that in the rear chamber exceeds 19.5MPa during operation, it overcomes the force of spring, opens sliding spool 7 and oil flows back 31

to the tank. At this time the, check valve 5 is closed under the oil pressure. When the bucket tilts forward and rapidly dumps the load, because there is not enough time for the distributing valve to provide enough oil to fill the vacuum formed in the front chamber, oil in the oil tank opens the check valve 8 under atmospheric pressure and replenishes the front chamber of the tilting cylinder, thus preventing the phenomenon of “cavitations” and assuring the normal operation of the system. So that, for cleaning the material in bucket, the impact between bucket and limit block is allowed.

Fig 3.6-3 Rear chamber double-action safety valve Fig 3.6-4 Front chamber double-action safety valve 1. Screwed cover 2. Pressure adjusting screw 3. Nut 4. Copper washer 5. Spring 6. Valve case 7. Spool 8. Check valve spool 9. Spring 10. To rear chamber of tilting 11. To return circuit 12. To front chamber of tilting

Another function of the double-action safety valve is that when the bucket is tilted to the extreme forward position and the arms are to be raised, due to the uncoordinated movement of the working mechanism linkage, the piston rod of the bucket tilting cylinder will be forced outwards and the pressure of the front chamber is increased. The front double-action safety valve overflows under overload and the rear double-action safety valve replenishes oil to the vacuum. On the contrary when the arms descend with the bucket tilted to its backmost limit, the piston rod retracts, and the pressure in the rear cavity increases and forms a vacuum in the front chamber. The oil from the oil tank now forces the check valve of the front double-action safety valve to open and replenish. Thus, the double-action safety valve solves the interference of implement, stables the system and safeguards the components. 3.7 Steering system Full-hydraulic steering is adopted on this machine. Large displacement steering gear is applied in this system. The principle of the steering system is shown in fig 3.7-1 “Principle diagram of steering system”.

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Fig 3.7-1 Principle diagram of steering system 1. Steering cylinder 2. Model FKAR valve 3. Model BZZⅠ-1000A steering gear 4.Gear pump 5. Coarse filter 6. Oil tank 7. Fine filter 3.7.1 Full-hydraulic steering gear (as shown in fig 2.7-2) Principle: Model BZZ-1000 full-hydraulic steering gear is a cycloidal rotary valve type steering gear consisting mainly of a servo-valve and a pair of meshed cycloidal wheels. It features maneuverability, feather touch steering,

Fig 3.7-2 Full-hydraulic steering gear 1. Coupler 2. Rear cover 3. Case 4. Spring 5. Yoke 6. Valve sleeve 7. Spacer disk 8. Connecting axle 9. Rotor 10. Front cover 11. Valve spool 12. Steel ball 13. Stator reliable operation, compact design, ease in installation and capability of implementing manual steering when the engine stops. In operation, the steering wheel is connected to the steering gear through the steering shaft. The steering gear is mounted together with model FKA valve block which includes a bidirectional damping valve, an overflow valve and a check valve. The overflow valve, situated between the inlet port and the return port, limits the maximum pressure of the steering gear in order to protect the steering system. This valve 33

assures load-relief when steering cylinders reach their end positions. The function of the damping valve is to prevent high pressure in the hydraulic system caused by external shock on the wheels and to protect the hoses and other mechanisms from damage. The check valve prevents vehicle skewing caused by high pressure oil passing through the steering gear in the reverse direction when Overpressure in cylinder side exceeding the pump pressure. It also prevents air from entering the pump during manual steering. 3.7.2 Steering pump The steering pump in this machine is Model CBG2080 gear pump. It is a fixed axle clearance and externally meshed type gear pump of 3-piece construction with left rotated and single key. The clearance between the end face of the gear and the side plate is fixed. The radial clearance between the gear circumference and the pump case is fixed also.

Fig 3.7-3 Steering pump 1. Flat key 2. Retainer ring 3. Seal ring 4. Front cover 5. Seal ring 6. Bearing 7. Cylinder pin 8. O-ring 9. Side plate 10. Pump case 11. Drive gear 12. Retainer ring 13. Seal ring 14. Rear cover 15. Bolt 16. Driven gear 3.7.3 Steering cylinder The steering cylinders are of single stage, double action and single piston rod type, as shown in fig 3.7-4. The end of piston rod connects to the rear frame and the other end to the front frame. The piston rod chamber of the left cylinder connects to the large chamber of the right steering cylinder via a hose and the large chamber of the left cylinder connects to the piston chamber of the right steering cylinder. When steering is applying, the piston moves to-and-for under the oil pressure, which drives the front and rear frame to rotate relatively.

34

Fig 3.7-4 Steering cylinder 1. Guide ring 2. Guide sleeve 3. Cylinder body 4. Piston rod 5. Piston 6. Composite seal ring for bores 7. Support ring 8. Knuckle bearing 3.8 Gearchange system The function of the gearchange system is to control the transmission control valve, then to change the driving direction and speed of the vehicle. The gearchange system is composed of shift lever, upper linkage, coupling, 1ower linkage and column, as shown in fig 3.8-1.

1. Gearchange lever 2. upper linkage 3. Coupling 4. Column 5. Lowering linkage The transmission valve includes four, corresponding to reverse, neutral, 1st-gear and 2nd gear. 3.9 Implement The implement of the loader is composed of four main components: the bucket, lifting arms, draw-bar and rocker arm, as shown in fig 3.9-1.

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Fig 3.9-1 The implement mechanism 1. Bucket 2. Draw-bar 3. Rocker arm 4. Lifting arm 5. Seal 6. Sleeve 7. Pin 8. Wearable plank The lifting arms are supported on the front frame by their rear ends. They form a Z-bar linkage together with the rocker arm, the draw-bar and the bucket. The lifting or lowering of this linkage is actuated by the extension or retraction of the lifting cylinders. In this linkage system, a single rocker arm is used, which is mounted on the cross beam. With the lifting arms staying in any position and under the actuation of the bucket-tilting cylinder via the linkage, the bucket can be rotated forward or backward around its lower pivot. When the tilting cylinder is locked and the arms are lifted or descended under the actuation of the lifting cylinders, the angle between the bucket bottom plane and the ground level can be held in a relatively constant range so that the material in the bucket will not spill. The bucket is the equipment to cut, collect, transport and dump material. The standard (universal) bucket of this loader is for loading materials of density ranging between l.4 and 2.0 ton/m3 (e.g. sand, gravel, loose soil and etc.). The standard bucket is equipped with teeth making of highly wear-resistant alloy, which can be replaced when worn out. The cutting edge of the bucket is also pile-up welded with wearresistant alloy. The pins in all pivots of the implement mechanism are dust-sealed, as shown in fig 3.9-1, which may extend the service life of the pins and the sleeves. All pins should be lubricated every 50 work-hours to ensure their normal condition. The implement mechanism should be inspected for fracture at the welds and deformation periodically. Repair in time if any abnormality occurs. 3.10 Chassis The chassis of the loader consists of front frame, rear frame, pivot pin and the sub-frame, as shown in fig 3.10-1.

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Front frame and rear frame are the base of the loader and the support of all the components. They are connected together by pivot pins. The upper pin is mounted in knuckle bearing and the lower one, in radial roller thrust bearing. The front and rear frames can swing relatively within an angle of 38°. The sub-frame is mounted under the rear frame and is connected to the rear drive axle housing, allowing a vertical swing of 11°. So the loader may operate on uneven ground with all four wheels on the ground, assuring good stability. The connection between the sub-frame and the rear frame is mounted on slide bearings. The bearings between front and rear frames and those between the sub-frame and the rear frame should be lubricated every 50 work hours to ensure normal operation. 3. 11 Air conditioning system Air conditioning system is an optional scheme. It features cab pressure regulation, air filtering, and cooling or heating air supply. The cooling capacity ensures that the temperature inside is lower 5 to 7℃than outside in summer; The heating capacity ensures that the temperature inside is ranging from l5 to 28℃ in winter. The loader is suitable to operate in the northern and southern parts of China and in dusty environment. A regulation panel is mounted on the cover of evaporator behind the driver's seat for adjustment of cooling, heating or ventilation. Please refer to separate instruction manual of the air conditioner for its construction and operation principle. 3.12 Electrical and instrument system 3.12.1 General description The electric system of the loader consists of power supply circuit, starting circuit, and lighting circuit. All circuits are single-lined with the negative of 24 volts supply grounded to the chassis of the loader. The principle diagram of the electric system is shown in fig 3.12-1 and the wiring diagram in fig 3.12-2.

37

Fig

3.12-1 Electric system principle diagram The function of the power supply circuit is to provide electric power for the starting circuit and the lighting circuit. The batteries are charged when the engine is working on the rails. So the circuit can supply power when the engine is working at a low speed or when there appears a peak load on the circuit. The function of the starting circuit is to start the engine through driving the flywheel of the engine. 3.12.2 Structure and principle 1. Power supply circuit: This circuit consists of the batteries and the power relay. When starting the engine, turn the key to activate the power relay, the normal open contact of which closes the battery circuit and power is supplied to all circuits. 2. Starting circuit: This circuit consists of the starter and the starting relay. The working principle: Insert the key into the preheat start switch JK406 and turn the key 20° clockwise to position“Ⅰ” before starting the engine. Here electric current passes through “BR” of JK406 and the coil of the power relay JD231 to the negative of the batteries. The contact of JD23l is closed by the magnetic force creating by the coil of JD231. The contact makes that the negative of the two series-connected batteries closes the circuit via the pole “48” and the contact “47” of the power relay. When starting the engine, turn the key further clockwise 20° to position Ⅱ of switch JK406. The contact of JQ1A is closed for the magnetic force which is created by the circuit that electric current passes through JK406 B to JK408 R 2 then to JQ1A coil to JD195 to the ground. Thus, the current of starter relay winding passes through wire 38

32-contact of JQ1A-

solenoidactuatingcoil  starterfield  atarterarmatrue  holdingcoi l



-the ground. The

combined magnetic force of both coils pulls the core which in turn pushes the coupling via the yoke to engage the drive gear with the flywheel. The other end of the core pushes at the same time he disk contact Q to close the armature circuit and an large current passes through thick wire 51 – contact Q – starter field – starter armature – ground. The starter rotates to drive the crankshaft of the engine. During starting operation, the holding coil is functioning for normal starting operation for the solenoid actuation coil is of malfunction for the both ends is under the same tension while the disk contact Q is closed. With the engine has been starting, the key on JK406 returns to position Ⅰ, terminal R2 is cut off, relay JQ1A is not energized and its N. O. contact opens. A portion of the main current passes through actuating coil - holding coil - ground. Since the winding directions of the two coils are the same while the currents passing by them are in opposite directions, the magnetic forces produced cancel each other. The core is demagnetized and returns instantly to its original position and the starting is accomplished.

A branch of the current at terminal 32 passes through regulator FT221 to coil S1a then to the ground. The magnetic force created by coil S 1a closes the contact of the circuit relay that makes the alternator establish its voltage rapidly. To stop the loader, turn the key in switch JK406 counterclockwise 20° back to position “0”, the power relay JD231 is not energized. Its N. O. contact opens to cut off the power supply. 3.12.3 Points to be noticed 1. Storage battery Two model 6-Q-195 starting batteries, each of rated voltage 12V and capacity 195 ampere-hours are connected in series on the loader. The operating voltage is 24V. Cautions in the usage of the batteries 39

①The connection between the wire terminals and the battery poles should be tightly secured. ②Keep the battery top clean and dry. Filler plugs should be tightened with their vent unobstructed. ③Check electrolyte level and density regularly. Fill in distilled water when level is low. Never fill with sulfuric acid. The electrolyte density should be adjusted according to local temperature. ④Check the discharge status of the battery regularly. Batteries should not be discharged for over 50%. Full charge should always be maintained especially in winter to avoid freezing of the electrolyte owing to reduced density. ⑤The charging current should not exceed 20A during operation. ⑥For stoppage over half a month, the batteries must be fully charged before storage, and charged monthly during storage with a current of 9A for 6 to 8 hours to prevent damage of the batteries. 2. The starter The starter used in this loader is model QD214-4 pole, series excitation DC motor, with rated voltage 24V, maximum output power 6.6kw and maximum torque 58. 8N·m.The starter is equipped with a drive gear meshing organ. The rotation is clockwise viewed from the driving end. Cautions in the usage of the starter 1 The operating duration of the starter should not exceed 15 seconds. If the starter is to be used twice, the time interval between two starting operations should be more than 1 minutes. ② Never turn the preheat start key again until the engine and the starter stop completely. Otherwise, shock between flywheel gear ring and the drive gear may result. 2 When starting in winter, the oil supply cup for preheat should be kept full to avoid burning of the preheater. ④ Release the preheat- start key immediately after starting. If starting can not be accomplished after several consecutive attempts, inspect and remedy the trouble before trying again. CHAPTER 4 PERIODICAL MAINTENANCE 4.1 General description Kept technical maintenance strictly will extend the service life of the machine. Troubles can be located in early stage to reduce down-time and save repair cost. Please observe the schedule specified in this chapter and carry out inspection and maintenance accordingly. The schedule may be advanced when operating in adverse environment and under unfavorable conditions. Lubricating locations are shown in Fig 4-1. 4.2 Attention-getting items When applying lubricants, specified type should be used in order to reduce part wear and extend service life. If restricted by local conditions, substitutes of the similar.

40

Fig 4-1 Lubrication diagram of the loader 1. Grease 2. Engine oil 3. Brake fluid 4. Gear oil 5. Hydraulic oil 6. Torque converter oil The loader should be in a level position when lubricating. The lubricating tools and the lubricating part should be cleaned when lubricating. Lubricating oil in use should be maintained steady for a certain period of time to deposit and then use the upper portion of clean oil. The used oil should be drained when changing oil. Fill in with flushing oil and run the engine and all moving parts for several minutes. Drain the flushing oil after stopping the engine and fill in with fresh oil and then run the engine for several minutes, recruit the fresh oil to the stipulate level. For grease lubrication, apply grease until it is pressed out at the grease cup. Under extremely low or high temperature, use lubricants according to actual operating conditions for replacement. 4.3 Periodical maintenance Periodical maintenance is classified into 50, 200, 600 and 1200 hours intervals. 1. Every 50 hours (1) Tighten the bolts on the front and rear transmission shafts. (2) Check the oil content of the brake booster. (3) Check the oil level of the transmission. (4) Inspect and lubricate the throttle control, emergency brake and gearchange system. (5) Add grease to the grease points on the fan shaft, front and rear vehicle frame hinges, transmission shafts and sub-frame. 2. Every 200 hours (1) Check the tightness of the wheel rim bolts and brake disk bolts. (2) Check the oil level of the front and rear axle. (3) Clean the air filter. 41

(4) Clean the engine oil filter, fuel filter and the hydraulic transmission oil filter. (5) Measure the tyre pressure. The tyre pressure should be 0. 3MPa. (6) Check the electrolyte level, add electrolyte to the storage batteries and clean their surfaces. Smear a thin coat of vaseline on the terminals. (7) Inspect the various load-bearing welds and fixing bolts of the working mechanism, front and rear vehicle frame and sub-frame for cracks or looseness. 3. Every 600 hours (1) Check the cleanliness of the transmission oil. If impurities are found in the oil change the oil and wash the oil strainer at the same time. (2) Tighten the connecting bolts that fix the front and rear axle to the frames. (3) Inspect and adjust the emergency and parking brake. (4) Inspect the steering gear. Adjust if necessary. (5) Replace engine oil. 4. Every 1200 hours (1) Change the front and rear axle gear oil. (2) Clean the oil strainer and the oil tank bottom of the working mechanism hydraulic system and change the oil. (3) Clean and inspect the brake booster. Inspect the conditions of the sealing elements and springs. Change the brake fluid. prop up the vehicle frame, turn the wheels and check the sensibility of the brake. (4) Clean the diesel fuel filter of oil tank. (5) Inspect the working condition of the torque converter, transmission and steering gear. If necessary, dismantle and inspect the parts. (6) Inspect the sealing condition of the distributing valve and the working mechanism cylinders by checking the sinkage of the working cylinders. Measure the working pressure of the system, which should be 17MPa. If the sinkage exceeds the specified amount, dismantle and inspect the cylinders or the distributing valve. (7) Inspect the working mechanisms and vehicle frame to see if there are cracks on the welds. Inspect the tightness of the bolts and nuts on these parts. (8) Inspect the welds on the wheel rims and condition of load-bearing locations. CHAPTER 5 PROBABLE MALFUNCTION AND REMEDY 5.1 Transmission system Serial number Ⅰ

Trouble

Cause

Gear 1. Low oil level in the shifting transmission oil sump pressure of 2. Main oil line leakage all gears are 3. Transmission oil strainer all low clogged 4. defective oil pump 5. Improper adjustment of the pressure regulating valve

Remedy 1. Replenish oil to specified oil level 2. Inspect main oil line for leaks 3. Wash or replace oil strainer 4. Dismantle to inspect or replace the pump 5. Readjust according to the instruction 42

Ⅱ

Ⅲ

Ⅳ

Ⅴ

Ⅵ

Gear shifting pressure on a certain gear is low

Torque converter oil temperature is too high

6. Weak or broken pressure regulator valve spring 7. Jamming of pressure regulator valve or piston 1. Seal ring for that gear is damaged. 2. Seal ring on that oil line is damaged. 3. Oil passage to that gear is leaking 1.Transmission oil level is too low 2.Transmission oil level is too high 3.Low gear shifting pressure and clutch plates slipping 4.Clogging of the torque converter oil cooler 5.Too long continuous operation of the torque converter under heavy load 1. Gear not engaged

6. Replace the spring of the regulator valve 7. Dismantle to inspect and eliminate the jamming 1. Replace seal ring

Cause

Remedy

2. Replace seal ring 3. Find the leakage and repair 1. Replenish oil to specified oil level. 2. Drain oil to specified oil level 3. Refer to Ⅰand Ⅱ 4. Clean or replace oil cooler 5. Stop vehicle to cool down

Engine runs at full speed but vehicle 2. Pressure regulator valve spring fails to is broken 3. Refer to 1. 2. 3.and 4. of Ⅰ travel 1.Gear shifting pressure is low 2.Converter oil temperature is too high 3.Damage of the torque converter Inadequate impeller drive force 4.Damage of the overdrive clutch

1. Again shift to the desired position, or readjust gear shifting control lever system 2. Replace the spring 3. Refer to 1.2.3.and 4. of Ⅰ 1. Refer to ⅠandⅡ 2. Refer to Ⅲ 3.Dismantle and inspect the torque converter, replace the impeller 4. Dismantle and inspect the overdrive clutch, replace the damaged parts. 5.Inadequate output power of the 5. Check the engine engine Rising of 1. Oil leaks on the steering pump 1. Replace oil seal on the steering the shaft end. pump shaft end transmission 2. Oil leaks on the pump of the 2. replace oil seal on the pump of oil level implement mechanism the implement mechanism

5.2 Brake system Serial number Ⅰ

Trouble

Inadequate 1. leakage of the cylinder on the 1. Replace the rectangular force of clamp shaped seal ring service 2. Presence of air in the brake 2. Bleed the air brake hydraulic pipeline 3. Inspect the automatic drainage 43

3. Air pressure is too low 4. 5. 6.

1.

Ⅱ

Ⅲ

Ⅳ

Ⅴ

Brake fails to release properly

2. 3.

and pressure regulator, air tank and pipeline for leakage Wear of the booster leather cup 4. Replace the leather cup Oil leakage to friction lining 5. Inspect or replace wheel hub from the wheel hub ring Friction lining worn down to 6. Replace friction lining the limit Incorrect position of the brake 1. Readjust the position of the control valve push lever, piston push lever, inspect or replace rod jammed, valve return the spring of brake valve, spring ineffective or broken inspect the brake valve piston rod and drum diaphragm. Booster not working properly 2. Inspect the booster The brake piston of the 3. Inspect or replace the cylinder unable to return rectangular shaped seal ring Brake valve gate jammed by 1. Apply the brake several times foreign matters or damaged continuously to blow the dirt away or replace the valve Loose pipe joint or cracking of 2. Tighten the connection or the brake fluid pipe replace the brake fluid pipeline Leaks on the air tank check 3. Inspect the cause of leakage, valve or pressure controller replace check valve if necessary

Air tank 1. pressure decrease rapidly after 2. stopping the 3. vehicle(air pressure decrease exceeding 0.1MPa) 1. Loose the pipe joint 2. Abnormal operation of the compressor 3. oil draining screw plug on the Braking air oil water is loose pressure 4. Brake control valve gate or indication diaphragm rises slowly 5. Clogging of the pressure controller air vent of leakage of the check valve and drum diaphragm Inadequate 1. The clearance between the brake force brake drum and friction lining of the is too large emergency/ 2. The friction lining smeared by parking oil brake

1. Tighten the connection 2. Inspect the operation of the compressor 3. Tighten the plug 4. Inspect and clean the inside of the valve, find out the leak and repair 5. Clean the air vent, inspect the check valve and drum diaphragm, and repair. 1.Readjust according specification 2. Clean the frication lining

to

5.3 Hydraulic system Serial

Trouble

Cause

Remedy 44

number

Ⅰ

Ⅱ

Inadequate 1. Worn cylinder oil seals raising force 2. Serious wear of the of the arms distributing valve, fitting or clearance between valve spool inadequate and valve case exceed the bucket specified value tilting force 3. Oil line leakage 4. Serious interior oil leaking of the operation pump 5. Improper adjustment of the safety valve, system pressure too low 6. Clogged oil suction pipe and oil strainer Bucket tilting 1. Refer to Ⅰ and arm 2. The double-action safety lifting are valves are blocked slow when the engine run at full speed

1. Replace the oil seals 2. Dismantle, inspect and repair to achieve the specified clearance or replace the valve 3. Check for leakage in line and repair 4. Replace the operation pump 5. Adjust the working pressure of the system to specified value 6. Clean the filter and change the oil 1. Refer to Ⅰ 2. Dismantle and inspect the double-action safety valve

5.4 Steering system Serial number

Ⅰ strenuous steering

Trouble

Cause

Remedy

1.Slowly steering is Inadequate oil supply of Check the steering laborsaving, but fast is the steering pump pump strenuous Purge air in the Presence of air in steering steering system and 2. Bubbles in oil and system, inadequate oil in check the suction pipe irregular noise, cylinders oil tank , oil viscosity is of steering pump for move is uncertainty too high leakage, add specified oil to specified level 1.Foreign matters 1.Check strainer for between spool and seat damage of safety valve, pressure 3.Steering is lighter at no cannot be established 2.Clean the foreign load or low load but heavier due to untightness matters from the at heavy load 2.Adjusting crew loosen, spool and the seat pressure stetting then readjust on the changed test bench

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1.Steering wheel does not return to central position where the pressure drop increase 2.Evident increase in pressure pulsation, even the steering wheel cannot rotate 3. Steering wheel turns itself or swings left and right

Ⅱmalfuncti on in steering

4.Vehicle skewing, or steering cylinders not reacting or slow in reacting to the motion of steering wheel

5.Steering wheel does not return to neutral position itself, increased pressure drop in neutral position, steering gear not discharge when steering wheel stop turning

Ⅲ others

Spring in steering gear Replace broken Pin broken or deformed, Replace pin notch on connecting shaft connecting shaft broken or deformed Misplacement of rotor and connecting shaft, return spring broken, jamming of valve sleeve, spool or body Defective double-action safety valve, front and rear wheels not aligned, too much difference in air pressure of right and left tyres, Serious internal leakage in one cylinder, defective sealing in the neutral position of steering circuit 1.Non-concentric assembly of the steering column and the steering valve spool 2.Steering shaft rubbing against steering valve spool axially 3.Excessive resistance on steering column when turning 4.spring plates broken

or

Dismantle and replace the spring and reassemble

Check the doubleaction safety valve and relative accessory other

1.Dismantle, check and reassemble

2.Adjust

3.Reassemble after grinding 4.Replace spring plates

Oil leakage from the copulae of valve body, 1. Damaged seal ring 1. Replace the rings spacer, stator and rear cover, 2. Foreign matters in the 2. Clean it the seams between overflow seams valve cover and steering gear

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Chapter 6 Safety Items Warnings Please read and get familiar with all the safety items to prevent casualty accidents. This section includes safety items of optional equipment and accessories. Warning Prompt There are several safety signs on the machine. This section describes safety signs where they are pasted and hidden perils. Please spend some time to get familiar with these them. In order to make sure that you can read all safety signs, replace or clean them with cloth, soapsuds if the words or graphs on them are not illegible. Detergents, gasoline, etc should not be used. If any safety sign is damaged, lost or becomes illegible after cleaning, it is a must to replace it. If any part with a safety sign is replaced, make sure the new safety sign is pasted on the corresponding part for replacement. Warnings before start Wrong driving and maintenance may cause casualty accidents. It is required to read carefully the operation manual and relevant safety items prior to driving and maintenance. All operations shall be as per regulations. The operation manual shall be accessible for a driver in cab. Please contact the World dealers for the updated operation manual. Warnings concerning safe lock lever Please lower the operation machine down the ground and place the safety lock buckle (right side of driver seat) on the fixed locking position before leaving the cab so that accidents resulting in the unconscious misoperation of the control lever can be prevented when the mechanical control level is not fixed. Mechanical jerks or driver’s unconscious operations are potential to cause serious injuries. Warnings raising in reversing Before starting the vehicle or the operation machine, Beep to cause attentions of peoples around. Confirm that nobody is in the vehicle and around. Ask help when necessary, especially while reversing. It is imperative to comply with the requirements above even with reversing horn and rear reflector.

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No entry It is prohibited to enter the vehicle turning scope when operations are in process. Otherwise it may cause casualty accidents.

Safety items concerning frame lock While delivering or lifting, the vehicle body may suddenly turn back if the frame lock is not fixed. The turn-back may cause people around to be seriously injured or lose life. It is imperative to use the fixed link of frame lock while the vehicle body is delivering or lifting. It is required to use the fixed link of frame lock as required in servicing.

Chapter 7 General Notices of Safety Safety principle Only the personnel who have been specially trained and approved can operate and maintain the machine. All the safety regulations, preventive measures and instructions should be observed during operating and maintaining the machine. 48

When working with the other operators and the people who are in charge of directing the traffic in the work site, make sure that all the gesture signals are understood by them. Safety devices Make sure that all the hoods and covers are in the right positions and repair the damaged parts immediately. Use the safety devices such as safety joysticks correctly. Disassembly of any safety device is prohibited and the safety devices should maintain good working conditions. Safety joystick → refer to “Parking the machine”. Incorrect operation of any safety device could result in serious personal injuries or death. Unauthorized modification Any modification not authorized by World Group could cause dangers. Before modification, consult World Group. It will not be responsible for any injuries or damage caused by any unauthorized modification. Rules to be followed when maintaining and repairing machine Contact the machine only when all the parts are shut down completely

Prevention of crush or cut injury Do not insert your hands, arms or other parts of the body into or between the moving parts such as between the attachment and the oil cylinder or the bodywork and the attachment etc. When the machine is working, the gap between the moving parts could be changed, which may cause serious damage or injuries.

Precautions for accessories You should read relevant contents about the accessories in the User Manual and this manual before installing or using the optional accessories. 49

Do not use the accessories not approved by World Group, otherwise it may cause safety problems and affect normal operation and service life of the machine. World Group would not be responsible for any injury, accident or mechanical failure caused by using unapproved accessories.

Chapter 8 Operating Precautions Before starting engine Check if there is any abnormal condition around that may cause hazards before starting the vehicle. Check the landform and the soil texture to choose the best working method. If working on a road, there must be someone in charge of directing traffic. And the roadPadding blocks should be placed in order to ensure the safety of traffic and pedestrians. If working in a place where underground facilities, such as water pipes, gas pipelines, high voltage cables etc. are laid, the relevant company in charge should be contacted in order to avoid any damage. If working in water or through a sandy dike, the ground quality, water depth and flow rate should be inspected. Make sure not to exceed the permitted water depth In operator cab Never place any tool or spare part in the operator cab randomly as they could damage joysticks or switches. They should always be kept in the tool box in the vehicle at any time. Keep no oil, grease and other dirt on the floor, pedal and handrail in the operator cab. In operating machine While start Walk around the vehicle prior to getting up the vehicle and check that there are 50

not anybody and other obstacles. Do not start the engine if it is found that a warning mark is hanged on the control lever. It is allowed to start the engine only after the driver sits well. Do not let anyone enter the cab and other places of the vehicle except for the driver. For the vehicle equipped with the reverse warning buzzer, make sure that the buzzer can work normally. Inspections in reversing Before operating the machine or equipment, it is required to carry out the follows: Beep to cause attentions of peoples around. Confirm that nobody is around the vehicle, especially in the rear area. Ask someone check that everything is ok when necessary, especially while the vehicle drives reversely. Ask someone direct the traffic on site if the vehicle drives in the dangerous area or the field of vision is very tough.

Safety inspection Check and ensure the frame lock is in the neutral position before driving or operating the vehicle. Notices in travelling The bucket shall be on height of 40-50 cm off from the ground when it travels in the level road. The loader shall travel at low speed and keep stable in turning while travelling in the rough road. Do not turn suddenly. The steering wheel cannot work if the engine stops in travelling, which is very dangerous, requiring a sudden brake to stop the loader. Precautions during operating Do not get too close to the edge of a cliff edge. When building up a dam or shoving soil, or pouring down soil near a cliff, first pour down one stack and then push the first one with the second one. Do not bump a tip lorry or the side of a dug canal with the bucket. The load would be reduced suddenly when the loaded stuff are pushed off a cliff or when the vehicle arrives at the top of a slope. In this condition the speed would be increased suddenly so it must be decelerated. 51

Do not load windward to prevent dust. Ensure there is none in the working area when loading the tip lorry. Reduce surge as much as possible. Ensuring a clear vision When working in dark, the working and roof lights should be installed and the illumination facility should be established in the working site if necessary. Stop working when the vision is poor, such as foggy, snowy or rainy days. Do not work until the weather gets better to ensure safe working. Be careful to operate in snow When performing construction on the road covered with snow or ice, only a little slope could cause the vehicle in the danger of slipping to the edge. Therefore, drive slowly to avoid starting, turning or braking suddenly. Specially be careful when shoving snow on a road as the road shoulder and other things buried in snow can not be seen. Tire chains should be installed when traveling on the road covered with snow. Do not brake suddenly and lower down the bucket to the ground before stopping when traveling on the hillside covered with snow. The loading work varies greatly with different kinds of snow. Therefore the load should be reduced and try not let the vehicle slide. Do not crash the attachment Be especially careful to work in the place with limited height, such as in a tunnel, under a bridge or cable, or in a garage. Do not crash the attachment. Do not crash the attachment Be especially careful to work in the place with limited height, such as in a tunnel, under a bridge or cable, or in a garage. Do not crash the attachment. Breaking ,methods Do not step foot on the brake pedal unless it is necessary. Do not repeat breaking unless it is necessary. Brake with the engine (the gearbox cannot be placed in the neutral position) and always step on the brake pedal when traveling downhill. Working on soft ground Do not work in the places close to a cliff, crag and trench. If they collapse, you and the vehicle will fall down or overturn, resulting in a series of injuries and death. Remember the carrying capacity of these places would be decreased after storms. The soil nearby a trench is relatively loose and could collapse due to the weight and vibration of the vehicle. The fallen object protection system (FOPS) should be installed when working in the places with fallen gravels or other small objects. Working in the dangerous places with fallen stones or possibility of vehicle overturning danger is forbidden. Vehicle parking Park the vehicle on flat ground if all possible. If you have to park it on a slope, the wheels should be secured with wood blocks to prevent it from sliding. When parking on a road, be careful with other vehicles, banners and guardrails. Do not obstruct the traffic. Ensure the passing vehicles and pedestrians could see the skid-steer loader 52

clearly with the guardrails, signs, banners, lights and other necessary symbols. The attachment should be lowered down to the ground completely and the safety joystick should be in the locked position. Then stop the engine and lock all the devices with a security lock. Shipping When shipping the loader with a trailer, follow the regulations on the lengths, widths and heights of goods in each country and region and comply with all applicable laws. The lengths, widths and heights of goods should be considered when determining shipping routes.

Chapter 9 Precautions for maintenance Working under vehicle Before maintaining the vehicle or performing service under it, place all the movable attachments on the ground or to their lowest positions. Must secure the tires with blocks. Never work under a vehicle not securely supported.

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Rotating fans and belts Do not get close to the rotating parts and be careful not to get hung by other articles. If your body or any tool contacts the blades of fan, they may be cut off or flied. Therefore, do not contact any rotating part.

Precautions when machine is travelling or stopping Keep certain distance when machine is travelling, othewise it might cause accidents.

When the loader stops, don’t stay under the boom and bucket.

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Operating when chassis is lifted When operating with the chassis lifted, lock the front and rear frames with the frame locks and place the joystick in the middle position. Then lock the joystick with the safety lock and lock out the attachment and chassis. When lifting the vehicle with a jack, fill up the wheels on the other side with wooden blocks. Place blocks to fix the position after the vehicle is blocked. Maintaining tires It requires special tools and techniques to remove, repair and install the tires. Please go to the specified service stations for repairing.

Chapter 10 Safety Items in Operating Wheel Loader 1.General notices of safety 1.1 Before using the wheel loader, operator or relevant personnel shall read the instruction carefully and do what it stipulated. Otherwise major injury or unnecessary damage will be caused. 1.1.1 Only the personnel who have been specially trained and approved can operate and maintain the machine. 1.1.2 All the safety regulations, preventive measures and instructions should be observed during operating and maintaining the machine. 1.2 Operator shall dress conform to the safety requirements, wearing necessary protection equipment. 1.2.1 Avoid dressing loose clothes and wearing jewelries. Do not have long loose hairs as they could be snagged by the joysticks and moving parts, causing serious personal injuries and death. 55

1.2.2 Don’t wear clothes with oil stain, in case to cause fire. 1.2.3 Wear helmets, safety goggles, masks or gloves as well as safety shoes during operating and maintaining the machine, in order to prevent the splashed metal chips or other tiny particles from injuring you. 1.3 When working in a small or dangerous area, the warning sign is necessary. 1.4 Working after the operator got drunk or overwrought is absolutely prohibited. 1.5 If the operator who don’t fell well or take some medicine might causing sleep can’t operate the wheel loader. 1.6 When maintaining or inspecting in the articulation area,”anti-rotation rod” has to be installed, in order to prevent injury because of the rotaion of front and rear frame. 1.7 Up and down wheel loader in stairs when it’s stable. Don’t jump down the wheel loader when it’s travelling. 1.8 Don’t grab any operating rob when up and down wheel loader. 1.9 When refilling and inspecting the fuel or coolant, shuting down the engine first and prohibit smoking. Make sure the cover of fuel tank is closed. And the fuel and engine oil have to be put in some place which can’t be accessed without permission, in order to make sure its safety. 1.10 If the boom has to be lifted when maintaining, it has to be make the lifted boom stable and make sure it won’t fall down during maintaining. 1.11 The machine can’t be modified without permission. If it’s needed, then confirmed with relevant department of our company. It will not be responsible for any injuries and damage caused by any unauthorized modification. 1.12 When working with the other operators and the people who are in charge of directing the traffic in the working site, make sure that all the gesture signals are undersood by them. 1.13 When the operator left the cabin, the door and windows have to be locked. In order to cause the personal injury around the machine because of wrong operation by other people. 1.14 The working devices should be lowered all the way down to the ground when left the wheel loader. Then the engine should be shut down and all the devices should be locked. 56

1.15 When maintaining and repairing machine, all the parts have to be shut down completely. 1.16 The key should always be with the operator. The engine should be shut down and the key shall be pulled out before maintenance and repairing. 1.17 Before removing the cover of radiator, the engine should be shut down and let the radiator cool down; after slowly loosening the cover and releasing the high pressure gas inside, it can be removed in order not to cause any injury. 1.18 The hydraulic liquid might spray out when removing the cover of hydraulic tank. Slowly loosen the cover to release the pressure first before removing it. 1.19 Do not insert your hands, arms or other parts of the body into or between the moving parts such as between the attachment and the oil cylinder or the bodywork and the attachment etc. When the machine is working, the gap between the moving parts could be changed, which may cause serious damage or injuries. 1.20 When working in the site with asbestos dust, shall wear protecive masks and work back to the wind direction in order not to cause any health problem. 1.21 The machine has to equip an effective fire extinguisher, and know how to use it when there is a fire. 1.22 When maintaining and repairing the loader, please change the spare parts and oil strictly according to the instruction book and spare parts catalogue. Otherwise our company is not responsible for any safety problem occurred due to that. 2. Precautions before starting the engine 2.1 Check if there is any abnormal condition around that may cause hazards before starting the vehicle. 2.1.1 Inspect to make sure when starting the engine, no one is under the wheel loader or near its working site, in order not to injure other people. 2.1.2 If working on a road, there must be someone in charge of directing traffic. And the road padding blocks should be placed in order to ensure the safety of traffic and pedestrians. 2.1.3 If working in a place where underground facilities, such as water pipes, gas pipelines, high voltage cables etc. are laid, the relevant company in charge should be contacted in order to avoid any damage.

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2.1.4 If working in water or through a sandy dike, the ground quality, water depth and flow rate should be inspected. Make sure not to exceed the permitted water depth. 2.2 Preventing fire 2.1.1 Completely remove the wood chips, scrap of paper and other flammables on the engine box, which may cause fire. 2.2.2 Check if there is any leak in the fuel, lubricant and hydraulic system. Fix all leaks and get rid of all excess oil or flammable liquid. 2.2.3 Do not operate the vehicle near any flame. 2.3 Never place any tool or spare part in the operator cab randomly as they could damage or break the joysticks or switches. They should always be kept in the tool box in the vehicle at any time. 2.4 Inspect to make sure all the lamps are normal. Especially the turning and braking lamps. 2.5 Before starting the engine, the joystick has to be in neutral position. 2.6 Before starting the engine, the brake lever has to be in stopping position. 2.7 It is allowed to start the engine only after the driver sits well. 2.8 Do not start then engine if it’s found that a warning mark is hanged on the control lever. 2.9 Do not let anyone enter the driving line of the vehicle. 2.10 It’s better starting the engine in places with good ventilation. If inside of the room, put the exhuasting passage outside of the room, because too much engine emission might cause people to death. 3. Precautions after starting the engine and working 3.1 Before traveling, clean the blocks on the road, especially the iron block and ditches, to prevent breaking the tire. 3.2 Adjust the rear mirror, and make sure the operator has the best vision. 3.3 Make sure the horn, reversing sign lamp, buzzer and other safety devices are in normal condition. 58

3.4 When it’s about to travel or inspecting the flexibility of turning, you should press the horn first and then warn the surrounding people about safety. 3.5, Inspect the joystick, pedal and steering wheel before traveling. Make sure they are all in normal condition and then start to work. Especially inspect the turning and braking system. 3.6 Make sure no one is near the wheel loader, especially in the reversing area. If working in a poor vision site and dangerous area, there should be someone guiding the operation. 3.7 Overloaded working is prohibited. Because it might cause personal injury or machine damage. 3.8 Travel in slow speed when the loader is heavy loading and dischaging. Do not turning or braking suddenly, in order to prevent overturning, and cause personal injury and property loss. 3.9 When traveling in ramp, keep the bucket close to(about 200mm-300mm off from) the ground. It is required to quickly lower the bucket down to the ground at emergency, stopping the loader or preventing it from turning over. 3.10 Do not turn in ramp or traverse the ramp. It’s allowable to carry out there operations in the level ground. 3.11 Do not travel up and down in the grass, places with fallen leaves, or wet steel plate where it is easy to make the vehicle skid. The vehicle shall travel at very low speed along the slope edge. 3.12 The driver shall depress the brake and lower the bucket down in case the engine halts in ramp. Then use the parking brake. When the vehicle is travelling with loading, travel forward uphill and reverse downhill. 3.13 Avoid the tires slide when working and just two wheels on the ground, in order to reduce the abrasion and damage of the spare parts. 3.14 Do not get too close to the edge of a cliff edge. 3.15 Stop working when the vision is poor, such as foggy, snowy or rainy days. Do not work until the weather gets better to ensure safe working. Tire chains should be installed when traveling on the road covered with snow. 3.16 When working in dark, the working and roof lights should be installed and the illumination facility should be established in the working site if necessary.

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3.17 Be especially careful to work in the place with limited height, such as in a tunnel, under a bridge or cable, or in a garage. Do not crash the attachment. 3.18 When dragging, no one is allowed to enter into the area between towing vehicle and the vehicle to be towed when they are connected. Keep safe distance between people and machine to prevent accident because of the damage of towing device. 4. Vehicle parking 4.1 Park the vehicle on flat ground without danger of failing and slide, at the same time, low the device down to the ground completely. If you have to park it on a slope, the wheels should be secured with wood blocks to prevent it from sliding. After the engine shut down, it’s necessary to pull the control handle of the work device to ensure that various of hydraulic cylinder in the state of no pressure. When the vehicle on a slope, the tires should be placed well to prevent them from sliding. 4.2 Put the shifting lever and working operation lever and other levers in the neutral position. 4.3 Take away the key of frame lock and then shut down the master switch, finally close the windows and doors. 4.4 Never stop near flame and high temperature places in case of explosion and accident. 4.5 Make sure no person stand in the front of tires when inflating the tire by gas storage tank, in case of explosion and damage. 5. Precaution in the Process of Maintenance 5.1 Park the vehicle on hard and flat ground, and shut down the engine before checking and performing maintenance. Make the brake system on the state of brake, gearbox and work manipulation in neutral position, shut down frame lock and the vehicle’s doors. 5.1.1 Control levers and switches in the cab can not be operated randomly, they are only can be used by professional person and trained person in case of hurting people around the machine. 5.1.2 In the process of maintenance, warning signboard should be placed around the vehicles in order to tell other people not to operate the machine to ensure the safety.

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5.1.3 Only the professional personnel are permitted to maintain and repair the vehicle. 5.1.4 If someoneelse starts the engine or operates the joystick when you are maintaining or lubricating the vehicle, it may cause your injury or death.. 5.2 Person who perform maintenance work should extremely be careful and do not touch any moving parts like air fan, leather belt and transmission shaft. 5.3 Use tools that are proper to do the work. It is harmful to use broken, poor quality, defective or temporarily substituted tools. 5.4 Before maintaining the vehicle or performing service under it, place all the movable attachments on the ground or to their lowest positions and must secure the tires with blocks in case of damage. 5.5 When inspecting or maintaining the vehicle with the attachment raised, reliably uphold the raised moving arm so as to prevent the attachment from falling down. Furthermore, place the attachment joystick in the middle position and lock it with the safety lock in case of any damage. 5.6 Precautions for handling high pressure hose, do not forget there is pressure in the oil pipe all the time, before releasing the internal pressure, do not perform maintenance and checking in case of injury or damage. Do not use any high pressure pipes and rubbers in case of causing oil leakage, it may bring injury and damage. 5.7 When repairing the electrical system or using welding, you should disconnect the negative pole of storage battery to cut off the power. 5.8 Must check the machine before and after working everyday in order to ensure the safety of working. 5.8.1 Check whether working lamps and indicators are broken and check whether the electrical, gas and oil line are getting old and broken. 5.8.2 Check whether the dust in air filter of engine is effecting the air inlet. 5.8.3 Check whether the connection bolts are loose or falling off. 5.8.4 Check whether pins and connection bolts are loose. 5.8.5 Check the tire’s pressure, the tires need to be charged to the specified pressure( front wheel:0.30-0.32MPa, rear-wheel: 0.28-0.30MPa). Check whether the bolts in tires are loose. 61

5.8.6 Check whether there is the situation of leakage of oil, water, electricity and gas. 5.8.7 Check the cooling water volume, oil amount in the engine sump,breaking oil amount. When checking the water volume and oil amount, you should stop the engine, and check or refill them when the engine and cooler are cooling down. 5.8.8 Refill the grease to nozzles. 5.8.9 Check the situation of break pad and check whether they are need to be changed. 5.8.10 When disassembling or installing the storage battery: check the positive and negative poles, tighten the cover of storage battery reliably, when disconnecting it, the negative or ground pole should be removed first. 5.8.11 Avoid the metal devices connecting with battery poles, in order not to cause short-circuit. 5.8.12 At the moment when the vehicle stops, the cooling water in the engine and the oil in every part are all at high temperature and with high pressure. Under this condition, if the covers are removed to check the machine or exchange some parts, it may bring some injury and damage. So you should wait for them cooling down before performing check and maintenance. 5.9 When repairing the frame parts and using welding, you should emphasis on fireproofing. 5.10 Keep the vehicle clean and tidy all the time. Oil or grease overflow can be dangerous, so as scattered tools or broken parts because they may trip you down or injure you. 5.11 It requires special tools and techniques to remove, repair and install the tires. Please go to the specified service station for repairing. 5.12 Do not pour down waste oil into drainages or rivers. Make sure put the discharged oil into a vessel, never just pour down on the ground in case of any injury or damage. 6. Operating when machine is lifting and transporting 6.1 When the machine is lifting, engine should be shut down first, place the joystick and hand brake system in the middle position, and then lock the front and rear frame using the shutoff rod. 6.2 When lifting the vehicle with a machine, fill up the wheels on the other side with wood blocks, place blocks to fix the position after the vehicle is blocked.

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