Kubota K008-3 Workshop Manual page 346

(2)Troubleshooting
Troubles
Motor does not rotate.
Unstable rotation
Reverse rotating direction
Oil leak from connections
Noise is heard during rotation.
Speed is not changed over.
Causes
• Oil volume in tank is insufficient.
• Pump is broken.
• Malfunction of relief valve or low set pres-
sure
• Abnormal wear or scuffing of motor
• Shortcircuit in motor, entry of dust in valve
or valve plate
• Relief valve is set at low pressure.
• Air mixes in pump suction side.
• Reverse pipe connection
• Reverse motor valve timing
• Bolts are loosened.
• O-ring is bitten or broken.
• Floating valve seal is worn or damaged.
• Flaking, peeling or indentation is generated
at bearing.
• Gear oil is depleted.
• Sticking of 2-speed spool or pilot poppet, or
severe leak from them
• Orifice plate is clogged with dust.
• 2-speed pilot pressure is insufficient.
• Drain pressure is high.
IV-S-90
Remedies
• Supply hydraulic oil up to appropriate level.
• Replace pump.
• Disassembly and wash relief valve, and set
it at appropriate pressure.
• Disassemble and check motor, and replace
parts.
• Disassemble and wash.
• Set the relief valve at appropriate pressure.
• Connect pipe correctly.
• Set correct valve timing.
• Tighten bolts with appropriate tightening
torques.
• Replace O-ring.
• Replace floating valve seal.
• Replace bearing.
• Replace floating seal and supply gear oil.
• Replace end cover assembly.
• Wash orifice plate.
• Raise pilot pressure higher than 10 kgf/cm
+ drain pressure.
• Connect drain pipe or raise pilot pressure.
Courtesy of Machine.Market
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