LiuGong CLG835H, Service Manual

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4-53
January 24, 2017 Structure Function Principle
CLG835H Brake system
4. Troubleshooting for brake pump
Fault phenomenon of
oil pump
Possible cause Handling method
Oil pump is noisy
Air enters the system Tighten all joints
Oil supply is insufficient Refill the oil to a proper level
Oil is cold Operating in a low speed
Oil suction tube is blocked Remove the blocking object
Air filter in tank is blocked Clean or replace the air filter
Bad right alignment between pump and
input shaft
Check
Resonance is serious (resonance of pump
with peripheral components of oil tank and
pipeline)
Check if mounting bolts of pipeline and com-
ponents are tightened
Pump is slow at response
or has no response
Oil supply is insufficient Refill the oil to a proper level
Setting pressure of relief valve is insufficient Readjust the pressure of relief valve
Pump is worn or broken Repair or replace
Valve is worn or stuck or leaks Repair or replace
Oil temperature rises
Setting pressure of relief valve is too low
Adjust the pressure or replace the relief
valve
Low viscosity of fluid Replace with recommended hydraulic oil
Oil is dirty Replace the hydraulic oil
Low oil level Refill hydraulic oil properly
Pump is worn or broken Repair or replace
Oil foaming
Air enters the system through oil suction
tube
Tighten all joints
Low oil level Refill hydraulic oil properly
Lip type seal ring (oil seal)of main revolving
shaft is worn or damaged Replace the lip type seal ring (oil seal)of
main revolving shaft
The flow or pressure of
pump is insufficient
Side plate is broken Replace side plate
Relief valve fails Replace relief valve
Air enters the system Tighten all joints
Oil still leaks after replac-
ing the lip type seal (oil
seal)of main revolving
shaft
Worn lip type seal ring (oil seal) of revolving
shaft causes damage to the sealing area of
drive gear shaft
Replace the drive gear shaft
Seal ring is worn or damaged Replace the seal ring