ZX670-3 ZX870-3 EX1200-3 9260731 4653603 HPV145D Hydraulic Main Pump Assembly Compatible with Hitachi

1. Product Overview & Wholesale Price Range

The Hitachi ZX670-3 / ZX870-3 / EX1200-3 Hydraulic Main Pump Assembly (OEM Part # 9260731 / 4653603 / 4642948 / HPV145D) is an ultra-high-capacity dual axial piston tandem variable displacement pump engineered for 67-to-120-ton heavy mining excavators working under continuous open-pit granite quarrying, rock ripping, and mass excavation environments.

• Factory Wholesale Price: $8,800 – $16,800 USD (Direct manufacturer pricing — Save up to 50% vs regional dealer markups)
• MOQ & Bulk Discount: 1 Unit (Tiered wholesale discounts available for batch container orders)
• Lead Time: 1–3 business days (Large factory stock ready for immediate worldwide dispatch)
• Warranty: 12 Months full replacement warranty with 100% bench pressure test video proof

2. Application Worksite Checklist (施工场景清单)

Engineered with high-strength alloy swashplates and heavy-duty roller bearings to handle continuous 380 Bar pressure peaks:

• Heavy Open-Pit Rock Mining & Quarrying: Massive continuous hydraulic flow output under high working pressure for rapid rock truck loading with Hitachi ZX870-3 and EX1200-3 excavators.
• Deep Mass Foundation Excavation: Dual-circuit hydraulic stability during simultaneous boom lifting, bucket curling, and swing cycles on 80+ ton mining excavators.
• Highway Infrastructure & Heavy Trenching: Precise electronically-controlled displacement for fuel-efficient long-hour earthmoving work.
• Demolition & Heavy Concrete Crushing: Reinforced cast iron pump housing protects against continuous high hydraulic pressure shockwaves from heavy shear and breaker attachments.

3. Hydraulic Main Pump Troubleshooting & Diagnostic Guide (液压泵常见故障排查)

If your Hitachi 67–120 ton heavy mining excavator is exhibiting hydraulic system failure, consult the diagnostic guide below:

• Fault 1: Cold Machine Operates Normally, But Machine Slows Down & Drops Pressure After 1 Hour (冷车正常,热车掉压发慢)
  Root Cause: Thermal expansion wear gap between the piston shoes, cylinder block, and distributor valve plate, causing internal high-pressure oil thermal bypass.
  Solution: Replace with a complete drop-in HPV145D main pump assembly (OEM 9260731) or perform a complete rotary group overhaul.
• Fault 2: Engine Stalls or Overloads When Actuating Hydraulic Boom/Arm (憋车/发动机过载熄火)
  Root Cause: HPV145D pump regulator power-control spool jammed or hydraulic pilot regulator valve miscalibrated.
  Solution: Recalibrate HPV145D regulator pilot valve or replace the complete regulator assembly to restore engine horsepower matching.
• Fault 3: Hydraulic Oil Leakage From Drive Shaft Seal Area (主驱动轴封高压串油漏油)
  Root Cause: Clogged casing drain circuit line causing excessive internal housing backpressure, blowing out the drive shaft skeleton seal.
  Solution: Flush housing drain lines, replace front drive shaft seal, and check gear pilot pump relief pressure.
• Fault 4: Abnormal Cavitation Noise or Severe Vibration From Main Pump (泵体异响抖动/气蚀)
  Root Cause: Air suction at hydraulic inlet lines, contaminated oil suction filter, or worn drive shaft support bearings.
  Solution: Replace suction line seals, flush hydraulic fluid tank, and replace drive shaft roller bearings.
• Fault 5: Black Metallic Filings Found Inside Hydraulic Tank Filter (油箱内有黑粉或金属屑)
  Root Cause: Severe friction galling on swashplate shoe bronze layer or cylinder block face failure.
  Solution: Flush entire hydraulic piping system, clean main control valve, and install a new HPV145D main pump assembly.

4. Hot Machinery Replacement Parts Recommendation (5大品类热门推荐表)

Explore our factory-direct replacement hydraulic components compatible with major global excavator brands:

5. Frequently Asked Questions & Technical Support (QA 问答专区)

Q1: How do I verify if this HPV145D main pump fits my Hitachi ZX670-3 or ZX870-3 excavator?
A: Check your original pump nameplate for OEM numbers 9260731, 4653603, or HPV145D stamp. You can also send us your machine serial number for instant fitment verification.

Q2: My Hitachi ZX870-3 excavator stalls the engine when digging heavy granite. Will replacing the HPV145D pump solve it?
A: Yes, engine stalling is usually caused by a faulty HPV145D pump regulator valve failing to stroke down under load. Installing our pre-calibrated HPV145D pump restores correct engine power matching.

Q3: Is this Hitachi ZX870-3 HPV145D hydraulic main pump bench tested before shipment?
A: Yes, every single HPV145D pump undergoes a 5-step factory bench test, verifying pressure up to 380 Bar and volumetric efficiency above 95%. A live test video is provided before shipping.