SH120-2 SH120A2 KHH0272 KHH0273 AP2D36 Hydraulic Main Pump Assembly Compatible with Sumitomo Uchida Rexroth

1. Product Overview & Wholesale Price Range

The Sumitomo SH120-2 / SH120A2 Hydraulic Main Pump Assembly (OEM Part # KHH0272 / KHH0273 / KRJ1418 / AP2D36 / K3V63DT) is a dual axial piston variable displacement main pump engineered for 12-to-13-ton mid-size excavators operating under continuous trenching, road grading, and earthmoving works.

• Factory Wholesale Price: $2,300 – $4,200 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 test video proof

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

Precision-matched flow control designed to deliver smooth hydraulic displacement under continuous 300 Bar working pressure:

• Urban Infrastructure & Utility Trenching: Fine hydraulic metering for smooth boom and arm excavation in narrow ditches with Sumitomo SH120-2 excavators.
• Road Repair & Foundation Earthmoving: Sustained working pressure for rapid bucket loading cycles on Sumitomo SH120A2 excavators.
• Forestry Land Clearing & Agriculture Drainage: Thermal-resistant seal groups prevent oil bypass during long continuous operating hours in hot climates.
• Demolition & Concrete Breaking: Reinforced pump housing protects against severe pressure shockwaves from hydraulic hammer attachments.

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

If your Sumitomo 12–13 ton 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 AP2D36 main pump assembly (OEM KHH0272) or overhaul the internal rotary group kit.
• Fault 2: Engine Stalls or Overloads When Actuating Hydraulic Boom/Arm (憋车/发动机过载熄火)
  Root Cause: Main pump regulator power-control spool jammed or hydraulic pilot regulator valve miscalibrated.
  Solution: Recalibrate pump regulator pilot pressure 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 line causing excessive internal housing backpressure, blowing out the front 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 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 Sumitomo SH120A2 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 main pump fits my Sumitomo SH120-2 or SH120A2 excavator?
A: Check your original pump nameplate for OEM part numbers KHH0272, KHH0273, or AP2D36 stamp. You can also send us your machine serial number for instant fitment verification.

Q2: My Sumitomo SH120A2 excavator slows down after 1 hour of digging. Will replacing the pump solve this?
A: Yes, thermal slowdown is caused by internal pressure leakage inside the worn pump cylinder block. Installing our new Sumitomo SH120A2 pump restores full hydraulic speed and digging power.

Q3: Is this Sumitomo SH120A2 hydraulic main pump bench tested before shipment?
A: Yes, every single main pump undergoes a 5-step factory bench test, verifying pressure up to 300 Bar and volumetric efficiency above 95%. A live test video is provided before shipping.