40
6 Reason and resolution
6.3 Hydraulic
Problem
Reason
Solution
Broken pump coupling.
Check and replace.
Insufficient work oil.
Add work oil
Can not lift or
vibrate the shovel
Suck in air from the interface of suction pipe.
Check the position where air
enters and fasten the interface bolt
or replace interface
Insufficient function due to the wear and tear
of the hydraulic pump.
Check and replace.
Set pressure drop in the port safety valve or
keep in open.
Check and readjust or replace.
Insufficient work oil or improper viscosity.
Add oil or replace.
Suck in air from the interface of suction pipe.
Check the position where air
enters and fasten the interface bolt
or replace interface
Broken bobbin of the control valve and oil leak.
Check and replace the part.
The force of lifting
and vibrating of
the shovel is
insufficient or the
shovel is low in
speed
Bobbin can not realize the full stroke due to
the wrong adjusting of the control bar (cable).
Adjust handle bar (cable).
Wear and tear or damage of the hydraulic cylinder
piston gasket leads to the internal oil leak.
Check and replace the gasket.
Broken bobbin of the control valve and oil leak.
Check and replace the part.
The force of lifting
and vibrating of
the shovel is
insufficient
Set pressure drop in the port safety valve.
Check and readjust or replace.
Oil leak of the interface of rubber pipe and tubing.
Replace.
Parts of the control valve do not work.
（
Grab
foreign material
）
Check the position of the handle
bar and repair it. Check the
control valve and repair it.
Broken bobbin of the control valve.
Separate and check; then replace
the part.
Only complete
one action
Broken tube, tubing or interface. Replace.
Disagreement
between the
movement of the
handle bar and
the machine
Wrong connection of the tubing and rubber
pipe
Reinstall the tubing and rubber
pipe.
Insufficient work oil.
Add to the fixed amount of the oil
meter.
Suck in air from the interface of suction pipe.
Check the position where air
enters and repair.
Distortion of canal, tube and interface.
Repair or replace.
Abnormal sound
Cavity of the gear pump.
（
cold
）
Take warming machine running.
Viscosity of oil is too high.
Use the fixed oil.
The pressure of the main safety valve is not
adjusted in the right way.
Adjust in the right way.
When overloaded running continuously.
Stop continuously overloaded running.
The oil clarity rate in the pump or valve is reduced.
Check, clean and replace oil.
Temperature of
the work oil is
increased.
The piston is moved till the end but the handle
bar dose not return the holding position.
（
lightened continuously
）
The handle bar shall return the
holding position.
Summary of Contents for KDD03
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