Excavator Hydraulic Pump 708-27-04023 708-27-04022 Komatsu PC400-3 PC410-5 PC300-5 PC400-5 Main Piston Pump
Product Overview
High-performance main piston hydraulic pump designed for Komatsu excavator models PC400-3, PC410-5, PC300-5, and PC400-5. Compatible with part numbers 708-27-04023 and 708-27-04022.
Common Faults & Diagnostics
- Weak digging power when hot: Internal leakage from worn pistons, cylinder block and valve plate
- Engine lugging: Stuck or misadjusted TVC torque valve
- Slow operation: Low pilot pressure or stuck NC valve, worn pump core
- Noise & vibration: Cavitation, damaged bearing, piston shoe or pilot pump
- Large case drain flow: Serious internal wear of pump assembly
- Crawler drift: Unbalanced flow between front and rear pump
- Poor combined movements: Malfunction of NC negative flow valve