SK50SR KX161-3 Vio50 PVD-2B-40P RD511-61100 Nachi PVD-2B-40P Hydraulic Main Pump Assembly Compatible with Kobelco Kubota Yanmar Takeuchi
1. Product Overview & Wholesale Price Range
The Nachi Fujikoshi PVD-2B-40P Hydraulic Main Pump Assembly (OEM Part # PVD-2B-40P / RD511-61100 / 172458-73100 / PW10V00018F1) is a dual axial piston variable displacement pump with gear pilot pump engineered for 4.5-to-5.5-ton mini excavators operating under continuous trenching, landscaping, and residential earthmoving works.
- Factory Wholesale Price: $1,250 – $2,500 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 field operations:
- Urban Utility Trenching & Cable Laying: Fine hydraulic metering for smooth boom and arm excavation in narrow ditches with Kobelco SK50SR excavators.
- Residential Foundation & Earthmoving: Sustained hydraulic working pressure under 250 Bar for rapid bucket loading cycles on Kubota KX161-3 excavators.
- Agricultural Irrigation & Farm Clearing: Thermal-resistant seal groups prevent oil bypass during long continuous operating hours in hot climates.
- Demolition & Small Breaker Operations: 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 4.5–5.5 ton mini 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 valve plate, causing internal high-pressure oil thermal bypass.
Solution: Replace with a complete drop-in PVD-2B-40P main pump assembly (OEM RD511-61100) 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: PVD-2B-40P 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 inlet suction pipe, contaminated hydraulic tank 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 PVD-2B-40P 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:
| Category (品类) | Machine Model (适用型号) | OEM Part Number (零件号) | Compatibility (适配品牌) |
|---|---|---|---|
| Hydraulic Main Pump | SK50SR / KX161-3 / Vio50 | RD511-61100 / PVD-2B-40P | Compatible with Kobelco Kubota Yanmar |
| Hydraulic Main Pump | PC30-7 / PC35MR / TB135 | 708-3S-00030 / K3SP36C | Compatible with Komatsu Takeuchi |
| Hydraulic Main Pump | LiuGong 906E / Sany SY60 | 11C0678 / HP5V76 | Compatible with LiuGong Sany |
| Hydraulic Main Pump | CAT 306 / 306E | 458-1033 / AP2D28 | Compatible with Cater*pillar |
| Hydraulic Main Pump | EX120-5 / EX130-5 | 4372038 / HPV091DS | Compatible with Hitachi |
| Slewing Motor Assembly | SK120-5 / SH120 | YN15V00001F1 / MSG-85P | Compatible with Kobelco Sumitomo |
| Diesel Engine Assembly | PC400-7 / PC450-7 | 6251-11-1001 / SAA6D125E-3 | Compatible with Komatsu |
5. Frequently Asked Questions & Technical Support (QA 问答专区)
Q1: How do I verify if this Nachi PVD-2B-40P main pump fits my Kobelco SK50SR or Kubota KX161-3 excavator?
A: Check your original pump nameplate for OEM part numbers PVD-2B-40P, RD511-61100, or 172458-73100 stamp. You can also send us your machine serial number for instant fitment verification.
Q2: My Kubota KX161-3 excavator slows down after 1 hour of digging. Will replacing the PVD-2B-40P pump solve this?
A: Yes, thermal slowdown is caused by internal pressure leakage inside the worn pump cylinder block. Installing our new Nachi PVD-2B-40P pump restores full hydraulic speed and digging power.
Q3: Is this Nachi PVD-2B-40P hydraulic main pump bench tested before shipment?
A: Yes, every single PVD-2B-40P pump undergoes a 5-step factory bench test, verifying pressure up to 250 Bar and volumetric efficiency above 95%. A live test video is provided before shipping.
