CG938H Wheel Loader. Manual - part 11

 

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8.8 Welding Repair 

  Welding operation shall be conducted by competent welders and at places with proper 

equipments. Electric welding will generate gas, which may cause fire or electric shock in operation. 

The following instructions must be observed when welding: 

z  Disconnect the terminals of storage battery to prevent explosion of storage battery.   

z  Disconnect the engine’s power control unit and power socket connector of the electrohydraulic 

gear shift controller. 

z  Remove paints at places where are to be welded to prevent generation of toxic gas.   

z  If welding on hydraulic equipment or tubes, or at places very close to them, combustible steam 

and sparkle will be generated, which have a danger of cating fire or exploding. Avoid welding in 

such places.   

z  If the splashed sparkles of welding directly fall on rubber hoses, wires or pressured tubes, these 

pipelines may crack suddenly and the insulation husk of wires may be damaged. Use fire curtain 

to block the sparkles.   

z  When welding in places close to tyres, because tyre may explode, special care shall be taken.   

z  Wear protective clothes when welding.   

z  Keep the welding site well-ventilated.   

z  Clean up all combustible materials. Must prepare fire extinguisher at opertation sits.   

8.9 Repair of Cooling System 

z  When just completing operation, the temperature of hydraulic oil, oil and water in the engine 

and radiator is very high and is pressured. At this instance, any attempt to open the oil tank cap, 

radiator cap, fill oil or water, or replace filter may cause severe burnings.   

z  In order to prevent hot water from jetting out, turn off engine and allow the water cool down, 

screw off the caps slowly to release pressure. When checking whether the water temperature has 

dropped, put hand in front of the water radiator to feel the air temperature. Take care not to 

contact the radiator.   

z  In order to avoid burnings, do not touch engine or muffler, tail pipe, relay when the machine is 

hot.  

z  In order to avoid burnings, do not disassemble engine oil temperature sensor, water temperature 

sensor, torque conventer sensor or air conditioner water pipe when the machine is hot. The 

 

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cooling system contains alkline material; avoid contacting with skin or eyes.   

z  When replacing coolant, engine oil, transmission case oil, filter and other parts, select 

appropriate containers.   

z  Store of liquid and treatment of waste fluid shall comply with local environment protection laws 

and regulations.   

z  When disassembling linking pipelines of air conditioner compressor, forbid approach of open 

flame, or else toxic gas will be generated and poisoning will be inflicted. 

8.10 Repair of Hydraulic System

 

z  Before repairing hydraulic system, lock oil cylinder and other hydraulic devices, cool down 

hydraulic oil, release all system pressure of hydraulic system.   

z  Do not bend or hammer pressured pipelines. Do not install bended or damaged tubes or hoses on 

the machine.   

z  Repair in time any loose or damaged tubes or hoses of fuel or lubricant pipelines, or of 

hydraulic system.   

z  Leakage may cause fire, please repair or make replacement in time.   

z  Please check all pipelines (tubes and hoses) carefully and fasten all joints with specified torque. 

Do not check for leakage with bare hands; use boards or cardboards. Even the leakage of 

pressured fluid as minor as a needle eye may penetrate muscles and cause injuries. If solution is 

jetted to skin, it shall be treated within a couple of hours by surgeons who are familiar with this 

kind of injury. 

Note: when the following troubles are discovered, make replacement.   

1.  Damage or leakage of joints. 

2.  Wear-out of or cut on out layer and bareness of reinforcing wire. 

3.  Local bump of outer layer. 

4.  Obvious twist or flatness of hoses. 

5.  Wire in reinforcing layer is embedded into outer layer. 

6.  Displacement of end joints. 

z  Starting after system servicing: All control components shall be placed at the central position to 

make the pump under no load while starting up. Start up the engine and make it run for over 10 

minutes idly. After the oil temperature is increased, make the engine run under load in order to 

avoid poor oil absorption of the pump due to ropiness of the oil and damage of the pump 

 

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element. 

z  Any welding and mechanical processing on the accumulator’s cover are not allowed. After the 

connection of hydraulic pipes, the air in the pipe must be discharged by the discharge screw plug 

on the accumulator. The repairing  and pressure connection of the accumulator etc. shall be 

conducted after the pressure of the oil is released.   

Periodical maintenance of hydraulic steering system: 

1、Check all fastening positions and replace working oil after the initial driving of 50 hours; 

2、Check oil quantity in oil tank and check all fastening positions after driving for every 10 hours; 

3、Replenish grease at the front and rear supports of steering oil cylinder; 

4、Check system pressure (system pressure: 15.5MPa) after driving for every 500 hours; 

5、Replace working oil after driving for every 500 hours. 

8.11 Maintenance of Storage Battery 

Must abide by the following instrutions on storage battery: 

z  Never approach lighting cigarrettes or open flame to storage battery.   

z  When needing to contact storage battery in work, wear protective goggles and rubber gloves.   

z  Immediately use large amount of water to wash in case on splash of electrolyte of storage 

battery on clothes or skin.   

z  The splash of electrolyte inside storage batter into eyes may cause blindness. If electrolyte 

splashes into eyes, wash with large amount of water immediately and go to see doctor without 

delay.  

z  If having drunk electrolyte by mistake, drink large amount of water, or milk, or raw eggs, or 

rapeseed oil, and call for emergency aid of doctor or firstaid center.   

z  Before conducting works relevant with storage battery, turn off engine.   

z  Avoid contact with metalic items (such as tools) to cause shortcircuit between the positive and 

negative poles of the storage battery.   

z  When installing storage battery, connect the positive terminal first. When disassembling storage 

battery, disconnect the negative ternimal (at the side of ground line) first.   

z  When disassembling or installing storage battery, firstly check which one is the positive terminal 

and which one is the negative and fasten firmly    the nuts.   

z  When cleaning the top surface of storage battery, clean with cloth. Never use gasoline, solution, 

or any other organic solution or detergent.   

 

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z  Fasten firmly the top cover of storage battery.   

z  If the electrolyte of storage battery has frozen, neither charge the storage battery nor start engine 

by other power supplies. This is dangerous and may cause the storage battery catch fire. When 

charging the storage battery or starting engine by other power supplies, melt the electrolyte of 

storage battery before starting and check for leakages.   

z  Remove the storage battery from machine before charging.   

z  When repairing electric system or conducting electric welding on the machine, remove the 

negative pole of storage battery to prevent accidental flow of electric loop.   

8.12 Charge of Storage Battery 

If do not handle storage battery properly when charging it, the storage battery has a danger to 

explode. Therefore, please follow the charge procedures in handling rules and manual of storage 

battery, and abide by the following cautions: 

z  Charge in a place of good ventilation. Take off the top cover of storage battery. This will enable 

hydrogen diffuse and prevent explosion.   

z  Set the voltage of charge to the same as the voltage of storage battery to be charged. If the set of 

voltage is not correct, the charger may get overheated and catch fire, which may cause 

explosion.  

z  Connect the positive (+) charge clip of charger to positive (+) terminal of storage battery, then 

connect the negative (-) charge clip to negative (-) terminal of storage battery. The two terminals 

must be fastened.   

z 

If the charge rate of storage battery is lower than 1/10, adopt rapid charge mode and set the 

value below the rated capacity of storage battery. If the charge current is too big, leakage or 

evaporation of electrolyte may be caused, which may in turn cause fire or explosion.   

 

8.13 Maintenance of Tires 

z  Since an explosion of tire will push the components and parts such as tire, rim and driving axle 

to the a place about 500 meters or farther away from the machine, and the explosion and 

fragments will cause serious damages or a human casualty accidents, a normal pressure of the 

tire must be ensured without any overpressure. 

z  When the vehicle is running, the heat produced by high speed running will increase tire’s 

pressure, which is normal and do not try to lower it. Speed down or stop to cool the tire down.