Excavator Hydraulic Pump 708-2K-00330 708-2K-00240 708-2K-00014 Komatsu PC3000-6 PC4000-6 Main Piston Pump Pressure Pump Common Faults & Diagnostics Weak / slow movement on one pump or side: Internal leakage from worn pistons/valve plate/slippers in that section, reduced volumetric efficiency — measure each section's pressure and case drain flow to diagnose. All functions weak: Insufficient main pump pressure, failed main relief valve setting, severe pump internal leakage.