Hitachi EX120-2 EX120LC-2 Excavator Hydraulic Main Pump Assembly HPV091 9110712 Axial Piston Hydraulic Pump Replacement
Welcome to our heavy machinery hydraulic supply center. We specialize in providing the complete EX120-2 / EX120LC-2 excavator hydraulic main pump assembly (Part No. 9110712 / HPV091), precision-manufactured as a heavy-duty aftermarket replacement part compatible with Hitachi large engineering machinery equipment. Engineered to restore original system hydraulic flow and operating pressure, this axial piston pump guarantees high hydraulic efficiency under heavy digging loads.
- Product Name: Hydraulic Main Pump Assembly / Variable Axial Piston Pump
- Applicable Machine Models: Fit for Hitachi EX120-2, EX120LC-2, EX120-2m Excavators
- Hydraulic Pump Model: HPV091 / HPV091DW / AP2D36
- Reference Part Number / OEM: 9110712 / 9123282 / 9135071 / 4330219
- Core Internal Parts: Cylinder block, swashplate, piston plungers, valve plate, regulator & drive shaft
- Condition: 100% Brand New Aftermarket / Direct Fit OEM Replacement
- Testing & Quality Assurance: 100% Hydraulic Bench Pressure & Flow Tested, 6–12 months warranty included
Severe hydraulic wear causes loss of digging power. Replacing your worn pump with our complete EX120-2 hydraulic main pump assembly directly resolves these critical performance issues:
Cause: Scratched cylinder valve plate, worn pistons, or excessive internal oil slippage inside the pump.
Fix: Installing a new main pump restores full system pressure (34.3 MPa) and fast compound movement speeds.
Cause: Sticking pump displacement regulator or improper torque control adjustment overloading the engine.
Fix: Pre-calibrated hydraulic regulator ensures exact engine-pump power matching to prevent engine bogging.
Cause: Pitted drive shaft bearings, damaged swashplate cradle, or air aeration inside pump chamber.
Fix: Replacing the complete assembly eliminates whine and vibration, protecting main valves and cylinders.
Cause: Extreme internal fluid recirculation leakage generating excessive thermal friction.
Fix: Tight tolerance piston-cylinder clearances eliminate internal leakage, keeping oil temperatures normal.
Cause: Hardened drive shaft seals or damaged front casing seals due to thermal degradation.
Fix: Japanese high-pressure oil seals prevent external fluid leaks and safeguard hydraulic pressure.
Designed for reliable 12-ton hydraulic excavating tasks, this main hydraulic pump suitable for Hitachi EX120-2 excels in:
- General Excavation & Earthmoving: Maintains stable high-pressure oil delivery for boom, arm, and bucket operations.
- Trenching & Pipeline Works: Precise variable displacement control enables smooth multi-function movements.
- Demolition & Breaker Operations: Heavy-duty casing withstands constant hydraulic shock pressures.
Q: Where can I buy a replacement hydraulic main pump assembly compatible with Hitachi EX120-2?
A: You can purchase brand-new aftermarket EX120-2 hydraulic main pumps directly from us. We supply complete units tested on hydraulic test benches for direct bolt-on installation.
Q: What is the pump model and OEM part number for the EX120-2 hydraulic pump?
A: The pump model is HPV091 (or HPV091DW), and common OEM reference numbers include 9110712 and 9123282. Please check your pump tag or contact us for confirmation.
Q: Does this EX120-2 main pump come pre-adjusted?
A: Yes, the hydraulic regulator and flow rates are pre-calibrated to factory specifications before shipment, making it a drop-in replacement.
