Kubota KX080-3 Workshop Manual page 423

WSM KX080-3 Service
Failure symptom
3. Pump generates abnormal noise.
4. Overload to engine (Extreme lower-
ing of engine rotating speed or engine
stall)
5. Oil leaks.
Suspected causes
5. Suction resistance develops exces-
sively, resulting in generation of cavi-
tation due to abnormal
temperature, abnormal hydraulic oil
viscosity and other causes.
1. Air is sucked in due to lowering of
oil level in the tank.
2. Suction hose and pipe are inappro-
priate, resulting in increase of suction
resistance of the pump.
3. Cavitation is generated by clogged
strainer.
4. Inadequate capacity of the strainer
5. Cavitation generated due to too low
oil temperature or too high viscosity.
Defective coupling
6.
7. Pump vibrates with other equip-
ment.
1. Horse-power control torque is set
too high.
2. Clogging of internal pilot oil pas-
sage and orifice, or seizure or scuffing
of parts.
4. Seizure or abrasion of pump inter-
nal parts
1. Drain oil flowrate increases to boost
the pressure in the pump case until oil
seal is broken, thus resulting in oil
leakage. (Oil seal withstand pressure:
2
0.3 Mpa (3 kgf/cm , 43 psi)
IV-S-15
Remedy
Reduce suction resistance.
oil
Supply oil and eliminate air under no-
load operation.
Reduce suction resistance.
Clean the strainer. If clogging of
strainer is severe, flush the circuit and
replace hydraulic oil.
Select a strainer having the capacity 2
to 3 times larger than the maximum
discharge amount.
Carry out warming up operation.
Select oil and set the oil temperature
according to the instruction manual.
Check it for any deviation.
Check the set bolts for any looseness.
Re-adjust it by setscrew.
If the condition remains unchanged
even after re-adjustment by setscrew,
disassemble and check the pump.
Repair the pump.
Repair the pump.
Hydraulic system