中文
Welcome to Guangzhou HanRui Hydraulic Co., Ltd. We specialize in providing the complete HPV145 excavator hydraulic main pump rear cover assembly (rear head / end cover / back plate), 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 precision-machined valve plate seating and regulator ports, our pump rear covers eliminate pressure loss and hydraulic oil leaks under extreme working loads.
Heavy-Duty Application & Working Scenarios
Engineered to withstand continuous peak hydraulic pressure surges and high thermal loads during heavy excavation:
- Quarry Mining & Heavy Excavation: High-tensile ductile iron casting withstands continuous backpressure up to 350 Bar without housing deformation.
- Continuous Deep Trenching: Flat-lapped valve plate contact faces maintain 100% pressure tightness during continuous multi-function movements.
- Hydraulic Breaker Operations: Reinforced bolt mounting flanges absorb violent pressure shock waves transmitted from breaker attachments.
- Fleet Overhaul & Remanufacturing: Direct OEM-spec mounting ports ensure seamless drop-in fitment during shop main pump remanufacturing.
HPV145 Hydraulic Pump Rear Cover Fault Diagnosis & Troubleshooting
Facing main pump oil leaks or pressure loss? Worn rear covers account for significant hydraulic efficiency loss. Here is how our HPV145 Rear Cover Assembly resolves them:
1. Rear Cover Oil Leakage & Casing Cracks (后盖漏油 / 壳体开裂)
Symptom: Continuous hydraulic fluid leaking from the pump rear head junction or hairline cracks on the rear housing.
Cause: Structural metal fatigue or casting porosity failing under continuous high hydraulic backpressure.
Solution: High-density ductile iron casting with reinforced flange thickness resists cracking and stops external fluid leaks.
2. Valve Plate Seating Wear & System Pressure Drop (结合面磨损 / 系统掉压)
Symptom: Slow boom lifting speed, weak bucket break-out force, and speed loss when hydraulic oil gets hot.
Cause: Deep scoring or erosion on the internal valve plate seating face causing high-pressure fluid bypass.
Solution: CNC precision-lapped seating surfaces ensure zero internal fluid bypass and restore full 350 Bar working pressure.
3. Regulator Mounting Bore Galling & Engine Stalling (调节器座拉伤 / 闷车)
Symptom: Engine bogs down or stalls completely under heavy load due to erratic pump regulator response.
Cause: Internal scoring inside the rear cover regulator pilot oil passages sticking the regulator spool.
Solution: Precision-honed regulator mounting ports ensure smooth pilot spool movement and accurate pump destroking.
4. O-Ring Seal Channel Erosion & Seal Blowout (密封槽蚀损 / 冲毁密封圈)
Symptom: Sudden massive oil blowout between the rear head and main casing during high-pressure relief.
Cause: Corrosion or deformation of the perimeter seal channel groove under high casing pressure.
Solution: Deep-milled seal retaining grooves keep high-pressure O-rings securely in place under pressure surges.
5. Rear Head Overheating & Thermal Distortion (后盖变形 / 高温)
Symptom: Main pump rear housing temperature spikes rapidly after 30 minutes of 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 plate 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 | Hydraulic Pump Rear Cover / End Head | Compatible with Hitachi | Fixes Rear Oil Leakage & Pressure Loss |
| Cat 336GC / 336E | 509-5142 / K5V160DTP | Hydraulic Main Pump Assembly | Compatible with Cater.pillar | 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?
A: Direct from our Guangzhou factory, the wholesale price range for an HPV145 Hydraulic Pump Rear Cover (End Head Assembly) is $160.00 – $480.00 USD per piece, depending on regulator port 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 end cover?
A: The HPV145 pump rear cover is 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: What causes hydraulic oil leakage from the rear cover of the main pump?
A: Rear cover oil leaks are typically caused by deformed O-ring seal grooves, surface erosion on the valve plate seating face, or mounting bolt torque loss from excessive backpressure spikes. Installing a new precision-milled HPV145 rear cover restores seal flatness and cures oil leaks.
