Hitachi EX400-5 EX450-5 Excavator Hydraulic Main Pump 9129693 9153952 HPV145 K3V180DTH Main Hydraulic Piston Pump Replacement
Welcome to our heavy machinery hydraulic supply center. We specialize in providing the complete EX400-5 / EX450-5 excavator hydraulic main pump assembly (Part No. 9129693 / 9153952 / HPV145 / K3V180DTH), precision-manufactured as a heavy-duty aftermarket replacement part compatible with Hitachi large engineering machinery equipment. Engineered to restore original hydraulic system flow rate and high working pressure, this dual axial piston pump guarantees smooth compound movements and high digging performance under severe mining conditions.
- Product Name: Hydraulic Main Pump Assembly / Variable Axial Piston Main Pump
- Applicable Machine Models: Fit for Hitachi EX400-5, EX400LC-5, EX450-5, EX450LC-5, EX450H-5 Heavy Excavators
- Hydraulic Pump Model: HPV145 / HPV145DW / K3V180DTH
- Reference Part Number / OEM: 9129693 / 9153952 / 9255724
- Core Internal Parts: Dual piston pump housing, swashplate cradle, cylinder blocks, piston plungers, valve plates, regulator & pilot gear pump
- Condition: 100% Brand New Aftermarket / Direct Fit OEM Replacement
- Quality Testing & Warranty: 100% Hydraulic Bench Flow and Pressure Tested, 6–12 months warranty included
Heavy mining operations cause internal hydraulic wear over time. Replacing your worn unit with our complete EX400-5 hydraulic main pump assembly directly resolves these critical system failures:
Cause: Severe internal wear on the cylinder valve plates or piston plungers causing internal oil bypass.
Fix: Installing a brand-new main pump restores full system operating pressure (34.3 MPa) and fast cycle times for heavy digging.
Cause: Sticking pump displacement regulator or improper pilot pressure adjustment overloading the engine.
Fix: Pre-calibrated hydraulic regulators ensure precise engine-pump torque matching to prevent engine overload stalling.
Cause: Pitted drive shaft bearings, worn swashplate cradle bearings, or aeration in hydraulic lines.
Fix: Full assembly replacement eliminates mechanical whine, chatter, and vibration, protecting down-stream control valves.
Cause: Extreme internal fluid recirculation leakage generating excess thermal friction inside the casing.
Fix: Tight micron-level piston-cylinder clearances eliminate internal leakage and prevent fluid thermal degradation.
Cause: Hardened or damaged main drive shaft oil seals due to high operating heat and pressure spikes.
Fix: Built-in Japanese high-pressure oil seals prevent external oil leaks and protect hydraulic fluid levels.
Engineered for high-intensity 40-to-45 ton mining excavators, this main hydraulic pump suitable for Hitachi EX400-5 / EX450-5 excels in:
- Heavy Open-Pit Mining & Rock Excavation: Delivers continuous high-pressure flow for rapid full-bucket digging in hard rock.
- Large Mass Earthmoving & Quarrying: High pump displacement supports smooth compound boom, arm, and swing movements.
- Heavy Demolition Work: Reinforced casing resists continuous hydraulic shock loads during breaker usage.
Q: Where can I buy a replacement hydraulic main pump assembly compatible with Hitachi EX400-5 or EX450-5?
A: You can purchase complete EX400-5 / EX450-5 hydraulic main pumps directly from us. We supply brand-new, bench-tested complete units ready for immediate drop-in replacement.
Q: What is the pump model and OEM part number for the Hitachi EX400-5 hydraulic pump?
A: The primary hydraulic pump model is HPV145 (or K3V180DTH), and common OEM reference numbers include 9129693, 9153952, and 9255724. Please verify your pump nameplate before ordering.
Q: Does this EX400-5 hydraulic main pump include the displacement regulators?
A: Yes, it arrives complete with factory pre-calibrated hydraulic regulators and pilot controls, requiring no additional valve adjustments.
