Hitachi ZX650 ZX670 ZX870 ZX890 9260731 4653603 Complete Hydraulic Main Pump Assembly Compatible with Hitachi
The Hitachi ZX650 / ZX670 / ZX870 / ZX890 Hydraulic Main Pump (OEM Part # 9260731 / 4653603 / HPV145) is engineered for high-tonnage heavy excavators operating in severe mining and earthmoving environments.
- Price Range: $8,500 – $14,200 USD (Depending on model specs & rotary block configuration)
- Lead Time: 1–3 business days (Ready to ship)
- Warranty: 12 Months full replacement coverage
| Feature / Metric | Complete Drop-In Pump Assembly | Rotary Group Repair Kit |
|---|---|---|
| Price Range | $8,500 – $14,200 USD | $1,800 – $3,200 USD |
| Included Components | Dual Main Pump + Pilot Pump + Swashplate Regulator | Cylinder Block, Pistons, Valve Plate, Swash Plate |
| Downtime Impact | Ultra-short (2–4 hours plug & play) | Moderate to Long (12–24 hours full overhaul) |
| Core Problem Solved | Total hydraulic breakdown / Severe housing wear | Internal pressure drop / Minor volumetric leakage |
- Precision Bench Test: Dynamic flow and working pressure testing up to 350 Bar.
- Volumetric Efficiency Check: Ensured strictly above 95% under maximum operational load.
- Shaft Seal & Leakage Inspection: 100% high-pressure helium tightness verification.
- Regulator Calibration: Flow control valve presetted to factory OEM specifications.
- Anti-Corrosion Packaging: Sealed VCI rust-proof bag + heavy-duty export wooden crate.
- Issue 1: Machine slow & power drop when hydraulic oil warms up
Root Cause: Excessive wear on valve plate and cylinder block contact surface.
Solution: Replace with complete main pump assembly or rotary group overhaul. - Issue 2: Excessive vibration or abnormal pump cavitation noise
Root Cause: Air suction in inlet pipe or worn drive shaft bearings.
Solution: Inspect inlet suction filter and replace drive shaft assembly. - Issue 3: Oil leakage at main pump drive shaft seal
Root Cause: High pressure inside housing caused by blocked drain line / seal aging.
Solution: Replace shaft seal and clean main pump drain line circuit. - Issue 4: Sudden pressure loss in arm/boom function
Root Cause: Pump regulator spool jammed or relief valve seals damaged.
Solution: Recalibrate flow regulator valve or swap pump control section.
Q1: How do I verify if this main pump fits my ZX870 excavator?
A: Check your current pump nameplate for OEM part number 9260731, 4653603, or pump model numbers. You can also send us your machine serial number for instant fitment check.
Q2: Is this main pump compatible with original Kawasaki / Hitachi hydraulic systems?
A: Yes, all mounting dimensions, shaft splines, and port connections are 100% matching original OEM specs.