Gm Motor Troubleshooting - Kubota KX080-3 Workshop Manual

WSM KX080-3 Service
c. Troubleshooting
Phenomenon 1 Phenomenon 2
No pressure rise
Failure to run
Proper pressure
rise
Leak at mating
surfaces
Leak at casing
Oil leak
Leak at floating
seal
Leak at hydraulic
motor
More hydraulic oil
leak
Load-caused run
in operation
Parking brake not
working
Reduction gears casing surface
temperature too high
At low pressure
Zigzag travel
(when used as
travel motor)
At high pressure
Pump discharge
rate short
No speed-up
At GM motor
Unusual
operating noise
At piping
Failure to switch
from low to high
Two-speed
speed
selection
impossible
Failure to switch
from high to low
speed
Possible cause
Relief pressure setting too low
Pump defective
Directional control valve defective
Brake valve defective
Hydraulic motor defective
Reduction gears damaged
Overloaded
Mating surface scratched
Loose bolt
Loose plug
Broken by stone or the like
Sliding face worn out
O-ring crept
Loose bolt
O-ring damaged
Sealing surface scratched
Hydraulic motor volumetric efficiency drop
Brake valve internally leaky
Spring damaged
Friction disc worn out
Gear oil short
Pitching at bearing
Hydraulic oil into the casing
Left and right discharge rates not equal
Left and right hydraulic motor drain amounts
not equal
Left and right discharge rates not equal
Left and right hydraulic motor drain amounts
not equal
Left and right brake valve actions not equal
Relief pressure drop at left or right control
valve
Pump malfunctioning
Too much leak out of pump
Too much leak out of hydraulic motor
Hydraulic motor or reduction gears dam-
aged
Piping vibrated
High-pressure check valve malfunctioning
Selector valve malfunctioning
Pilot pressure too low
Two-speed selector piston malfunctioning
Selector valve malfunctioning
Two-speed selector piston malfunctioning
IV-S-140
Hydraulic system
Correction
Make correct setting.
Repair.
Repair.
Replace or repair the brake valve.
Repair.
Replace the GM motor.
Remove the cause of overload.
Smooth the surface with whetstone, sand-
paper or the like.
Retighten up.
Retighten up.
Replace the GM motor.
Replace the GM motor.
Replace the GM motor.
Retighten up.
Replace the O-ring
Smooth the surface with whetstone, sand-
paper or the like.
Replace the GM motor.
Replace or repair the brake valve.
Replace the spring.
Replace the friction and mating discs.
Add oil up to the proper level.
Replace the GM motor.
Replace the oil seal.
Repair the pump.
Replace the GM motor.
Repair the pump or control valve.
Replace the GM motor.
Replace the brake valve.
Make correct pressure setting. Replace
the relief valve.
Repair or replace the pump.
Repair or replace the pump.
Replace the GM motor.
Replace the GM motor.
Clamp the piping.
Repair or replace.
Repair or replace.
Set to the specified pressure.
Repair or replace.
Repair or replace.
Repair or replace.