Excavator Hydraulic Pump Komatsu PC200-6 PC210-6 PC240-6 PC270-6
Product Overview
Part Numbers: 708-2L-00423, 708-2L-00421, 708-2L-00461
HPV95 twin axial variable displacement main piston pump. Front and rear pumps integrated in one housing, directly driven by engine flywheel. It adopts Komatsu OLSS (Open Center Load Sensing System) with fully mechanical hydraulic regulation - No EPC solenoid valve.
Common Faults & Solutions
- Weak operation when hot, acceptable performance when cold: Wear of pistons and valve plate reduces volumetric efficiency and causes high-pressure internal leakage. Leakage increases when oil temperature rises. Hydraulic oil contamination is the primary trigger.
- Engine lugging & speed drop: Misadjustment or stuck spool of PC constant power valve. Pump absorbed power exceeds engine output, leading to lugging and speed drop under heavy load.
- Slow movement of whole machine: Stuck LS load sensing valve spool; worn internal pump parts leading to insufficient output flow, all machine movements slow down.
- Abnormal noise & vibration: Blocked suction filter, air ingress in suction pipe causing cavitation; damaged pump bearing or broken piston & shoe.
- Large case drain flow: Internal pump wear leads to high-pressure internal leakage, plenty of oil flows out from pump case drain port.
- Unbalanced combined movements: Stuck LS valve causes abnormal flow distribution, unbalanced force and speed when performing two operations at the same time.