Hydraulic Pump 708-2K-00120 708-2K-00122 708-2K-00123 Komatsu PC2000-8 Main Piston Pump for Excavator

The PC2000-8 is a Komatsu ultra-large mining excavator (PC2000-8 platform). The main pump is a multi-section large-displacement variable displacement piston pump (often a combination of multiple pumps supplying oil, e.g., 708-2K-00122 / 00123), With enormous displacement and very high power, the main pump is the most expensive and most critical component of the machine.

• 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.
• Pump abnormal noise / squealing: Insufficient suction or air ingress (with large suction flow, cavitation damages quickly), contaminated oil, internal pump wear.
• Engine lugging / speed drop under load: Seized power regulator/control spool; pump stays at large displacement.
• High oil temperature: Severe main pump internal leakage, high-pressure oil converting to heat.
• Oil leakage: Aged main shaft oil seal, worn end-cover O-rings, poor case drain.
• Jitter / pressure fluctuation: Air in the system, seized regulator, scored valve plate.

• Confirm the sub-model and the main pump configuration (multi-section combination).
• Confirm main pump assembly vs single pump section
• Confirm the part number based on the original old part number; part numbers for ultra-large displacement pumps are highly specific.
• Confirm condition: genuine new units are extremely expensive; remanufactured (Reman) units are the mainstream cost-saving option; aftermarket compatible units require extreme caution.
• Overhaul parts: cylinder block, valve plate, piston (slipper), retainer plate, swashplate, main shaft, bearings, seal kit.
• After-sales: warranty; fill with hydraulic oil before starting; after repair, replace all filters and clean the oil tank; for ultra-large pumps, prefer genuine or specialized-factory remanufacturing.