129
Fault
Cause
Action
The idle stroke of the
steering wheel is
over-sized.
The nuts of steering wheel are loose.
Adjust according to the requirement
The connection between steering column and
steering gear is worn or damaged.
Adjust as required
Steering torque is
insufficient
Loss flow of steering pump is inadequate.
Inspect or replace the steering pump
Pressure change of the safety pressure valve
Adjust its pressure (pressure)
Steering pump leaks seriously inside.
Repair or replace
Foot braking force is
insufficient
Main pump or sub-pump for braking leaks.
Replace the foot brake valve or rectangular
seal ring
There is gas in the brake hydraulic pressure
pipe line
Exhaust the air of the brake caliper
Low-pressure of the compressed air
Inspect the unloading valve of the air
compressor, air tank and tightness of the
pipeline
Diaphragm of the booster is damaged
Replace booster pump
Oil of the wheel rim drops on to brake disc due
to the leakage.
Inspect or replace the oil seal of wheel hub
The braking block is extremely worn to the limit. Replace brake block
Boom raising force or
bucket tilting force is
inadequate
Oil seal of the cylinder is worn or damaged
Change oil seal
Distribution valve is excessively worn, the fitting
gap between valve rod and valve body exceeds
the specified value.
Dismount and repair, to make the clearance
reach to the required value or replace the
distribution valve
Pipeline system leaks oil.
Find out the leaking point and remove it.
The working pump seriously leaks inside.
Replace working pump
Safety valve is adjusted improperly, the system
pressure is too low.
Adjust the system pressure to the specified
value
Oil tube and oil filter is blocked
Clean oil filter and change oil
After parking,
pressure of air
reservoir drops quickly
Air braking inlet valve is blocked by the dirt or
damaged
Brake several times. Blow the dirt or replace
the valve
Pipe joint is loose or pipe is broken
Tighten the joint or replace the brake hose
One-way valve of air inlet of air reservoir is not
sealed or pressure controller is not sealed
Check the reason for no sealing. Replace if
necessary
Leakage of brake
system
Pollution sources: oil, water, dust and impurity
Clean pipe line
With irregular brake oil
With regular brake oil
Air leakage resulting from worn washer
Clean the cylinder body, replace piston
washer
