Excavator Hydraulic Pump 708-3D-00020 708-3D-01020 708-3D-00030
Komatsu PC138US-8, PC120-8, PC110-8, PC130-8 Main Piston Pump
Common Faults
- Weak digging power when hot: Internal leakage caused by worn pistons, cylinder block and valve plate.
- Engine lugging: Stuck PC valve or malfunction of EPC solenoid valve.
- Slow actions & high oil temperature: Stuck LS valve or worn pump internals.
- Abnormal noise & vibration: Cavitation, damaged bearing or piston shoe.
- Large case drain flow: Serious internal wear of pump assembly.
- Unstable operation: Abnormal EPC signal or intermittent LS valve sticking.
- Pump fault code & low power: Failed EPC solenoid or damaged wiring harness.