中文
Welcome to Guangzhou HanRui Hydraulic Co., Ltd. We specialize in providing the complete HPV145 excavator hydraulic main pump rear cover and regulator assembly (rear head / servo control valve / pilot regulator), precision-manufactured as heavy-duty aftermarket replacement parts compatible with Hitachi, Kawasaki, and John Deere engineering machinery equipment. Cast from high-grade ductile iron with calibrated regulator spools, our pump rear heads eliminate engine stalling under load and restore accurate variable displacement flow control.
Heavy-Duty Application & Working Scenarios
Engineered to withstand continuous peak hydraulic pressure surges and high thermal loads during heavy excavation:
- Quarry Mining & Heavy Excavation: Calibrated regulator valve spools maintain exact power-matching with the engine during 350 Bar peak load digging.
- Continuous Deep Trenching: Precision pilot oil passages guarantee rapid, smooth displacement adjustment during compound movements.
- Hydraulic Breaker Operations: High-tensile ductile iron body absorbs intense hydraulic pressure shock spikes from breaker attachments.
- Fleet Overhaul & Remanufacturing: Pre-calibrated regulator assembly ensures direct drop-in setup during main pump rebuilding.
HPV145 Hydraulic Pump Rear Cover & Regulator Fault Diagnosis & Troubleshooting
Facing engine bogging or erratic pump flow? Regulator and rear cover wear account for over 85% of hydraulic control failures. Here is how our HPV145 Rear Cover & Regulator Assembly resolves them:
1. Engine Stalling / Overloading Under Heavy Load (控泵熄火 / 闷车)
Symptom: Engine bogs down or shuts off completely when raising the boom or curling the bucket under heavy load.
Cause: Sticking regulator spool or scored pilot valve bore in the rear cover failing to destroke pump displacement.
Solution: Precision-honed regulator spools and calibrated springs ensure accurate displacement reduction and prevent engine overload.
2. Variable Displacement Failure & Speed Hesitation (变量失灵 / 调速卡顿)
Symptom: Excavator hydraulic movements feel jerky or fail to accelerate when pilot pressure increases.
Cause: Internal wear on regulator pilot piston bores or clogged feedback oil orifices in the rear head.
Solution: Mirror-polished regulator spools provide instantaneous, smooth hydraulic flow adjustment.
3. Rear Head Oil Leakage & Seal Blowout (后盖漏油 / 冲毁油封)
Symptom: Hydraulic fluid leaking past the rear head mounting interface or regulator solenoid seals.
Cause: Deformation of O-ring seal grooves or mating face warpage under high backpressure surges.
Solution: High-density ductile iron casting with deep-milled O-ring seal grooves prevents fluid leaks and seal blowout.
4. Valve Plate Seating Wear & System Pressure Drop (结合面磨损 / 系统掉压)
Symptom: Slow attachment speeds and loss of hydraulic digging breakout force when oil heats up.
Cause: Deep scoring on the internal valve plate seating face inside the rear cover, causing high-pressure bypass.
Solution: Flat-lapped valve plate seating surfaces ensure zero fluid bypass and rebuild full 350 Bar operating pressure.
5. Rear Head Overheating & Thermal Distortion (后盖发热 / 高温)
Symptom: Main pump rear housing temperature spikes rapidly after 30 minutes of continuous operation.
Cause: Extreme friction heat generated by continuous internal high-pressure fluid recirculation.
Solution: Optimized thermal cooling fins promote rapid heat dissipation, preserving internal valve clearances.
Hot Popular Excavator Hydraulic Main Pumps & Spare Parts Catalog
Explore our factory-direct aftermarket catalog for major construction equipment brands:
| Machine Model (型号) | Part Number (零件号) | Component Name (品名) | Compatible Brand (适配品牌) | Target Fault Solved |
|---|---|---|---|---|
| ZX330 / ZX350 / EX300 | HPV145 Rear Cover & Regulator | Hydraulic Pump Rear Cover & Regulator | Compatible with Hitachi | Fixes Engine Stalling & Rear Oil Leakage |
| Cat 336GC / 336E | 509-5142 / K5V160DTP | Hydraulic Main Pump Assembly | Compatible with Caterpillar | Fixes Engine Stalling & Low Digging Pressure |
| SK330-8 / SK350-8 | LQ10V00018F1 / K3V180DT | Main Hydraulic Pump Assembly | Compatible with Kobelco | Fixes Pressure Instability & Internal Bypass |
| EX200-5 / EX200-6 / ZX200 | HPV0102 / HPV102 Housing | Hydraulic Pump Casing / Body | Compatible with Hitachi | Fixes Casing Leakage & Bearing Seat Wear |
| PC300-8 / PC350-8 | 708-2G-00020 / HPV160 | Hydraulic Main Piston Pump Parts | Compatible with Komatsu | Fixes Slow Movement & Pump Noise |
Frequently Asked Questions (Troubleshooting & Fitment)
Q: What is the price range for an HPV145 hydraulic pump rear cover and regulator assembly?
A: Direct from our Guangzhou factory, the wholesale price range for an HPV145 Hydraulic Pump Rear Cover & Regulator Assembly is $180.00 – $520.00 USD per set, depending on regulator valve options and order volume. Purchasing directly saves 30% to 50% compared to local OEM dealer prices.
Q: Which excavator models use the HPV145 hydraulic pump rear cover and regulator?
A: The HPV145 rear cover and regulator assembly are compatible with 30-to-35-ton excavators, including Hitachi ZX330, ZX330-3, ZX350, ZX350-3, EX300-2, EX300-3, EX300-5, EX350, and John Deere 330/370 excavators equipped with HPV145 main hydraulic pumps.
Q: How does a faulty hydraulic pump regulator cause the excavator engine to stall?
A: When the hydraulic pump regulator spool sticks or wears out, it fails to destroke pump displacement when hydraulic working pressure rises. This forces the hydraulic pump to absorb more torque than the engine can produce, causing the engine to bog down or stall. Installing a new HPV145 rear cover & regulator assembly resolves engine stalling under load.
