379-9740 20R-7880 Hydraulic Piston Pump for Caterpillar Equipment

Product Overview

Technical Specifications

General Series Specifications

• Pump Type: Swash-plate variable displacement axial piston pump (OEM-equivalent to Rexroth A10VO series)
• Rated Working Pressure: 28 MPa
• Maximum Peak Pressure: 35 MPa
• Control Type: Pressure-compensated variable control (DR type)
• Rotation Direction: Standard clockwise (viewed from shaft end)
• Housing Material: High-strength cast iron

Model-specific Parameters

1. Model: 379-9740 (Reman Part No.: 20R-7880)
   • Compatible Equipment: Caterpillar 854K wheel dozer, 992K wheel loader
   • Net Weight: 51.25 kg
2. Model: 271-2116
   • Compatible Equipment: Caterpillar D6T series track-type tractor (with C9 engine)
   • Nominal Displacement: 100 ml/r
   • Rated Speed: 1800 r/min
3. Model: 252-2680 (Reman Part No.: 20R-7023)
   • Compatible Equipment: Caterpillar 963D track loader (with C6.6 engine)
   • Nominal Displacement: 110 ml/r
4. Model: 244-2228 (Reman Part No.: 10R-8770)
   • Compatible Equipment: Caterpillar 420D, 430D backhoe loaders
   • Nominal Displacement: 71 ml/r
   • Net Weight: 36.46 kg
5. Model: 235-4110 (Reman Part No.: 10R-8696)
   • Compatible Equipment: Caterpillar 416D, 428D, 436C backhoe loaders (with 3054C engine)
   • Net Weight: 36.83 kg

Key Technical Advantages

1. OEM Dimensional Accuracy for Zero-modification Interchange

   Mounting flange, output spline and port positions are manufactured with strict tolerance per OEM drawings, with bolt hole deviation controlled within 0.02mm. It can be directly replaced without frame rework or pipeline modification, greatly reducing equipment downtime and overhaul cost.

2. Precision-lapped Tribological Pairs for Sustained Volumetric Efficiency

   Core friction pairs including cylinder block, pistons and valve plate are made of nitrided alloy steel with ultra-precision lapping, achieving surface flatness ≤0.001mm. The hydrostatic oil film support structure eliminates direct metal-to-metal contact, maintaining over 92% volumetric efficiency under heavy impact loads and delaying internal leakage failure.

3. Pressure-compensated Control for Optimized Energy Efficiency

   Equipped with DR-type pressure compensator, the pump automatically reduces displacement when system pressure reaches the set point, maintaining constant pressure and cutting wasted power consumption. Compared with fixed-displacement pumps, it reduces energy consumption by 15%-20% and improves machine fuel economy.

4. 100% Full-load Bench Testing for Factory Quality Assurance

   Every finished pump undergoes complete pressure-flow-response cycle testing on a hydraulic test bench, simulating real working conditions to inspect pressure holding, internal leakage and abnormal noise. Factory defects such as insufficient flow, pressure drop and stuck variable action are fully eliminated before shipment.

5. Optimized Flow Channel with Low Noise & Superior Self-priming

   Internal suction and discharge channels are optimized via fluid dynamics simulation, reducing oil turbulence and cavitation risk as well as operating noise and vibration. Excellent self-priming performance adapts to various tank layouts and works reliably in harsh field construction environments.

Application Areas

• Mining operations: Main hydraulic power source for large Caterpillar wheel loaders and track-type dozers, suitable for high-load ore loading and dozing work
• Infrastructure construction: Hydraulic systems for backhoe loaders and track loaders in earthmoving, material handling, road construction and site grading
• Municipal engineering: Hydraulic power units for municipal equipment, compatible with various attachments like hydraulic hammers and buckets
• Equipment overhaul: Hydraulic system refurbishment and faulty pump replacement for full-range Caterpillar equipment, suitable for used machine renovation projects

Expert Maintenance Tips

1. Pre-fill pump housing before installation: After long-term storage, fill the pump casing with clean ISO-VG46 anti-wear hydraulic oil through the drain port before installation. Never start the pump with an empty cavity, as dry friction will scuff slippers and valve plate.
2. No-load startup procedure: Turn the main relief valve to minimum pressure before first startup. Jog the engine to confirm correct shaft rotation, then gradually raise pressure to the rated value. Never start directly under high-pressure load.
3. Operating oil temperature control: Keep working oil temperature between 15℃ and 65℃. Install an oil cooler if temperature consistently exceeds 70℃, as high temperature accelerates seal ageing and breaks down lubricating oil film, drastically shortening pump service life.
4. System pressure limit: Never set the system safety relief valve higher than 35MPa peak pressure. Unauthorized pressure increase for faster operation will damage the variable spring and accelerate wear of friction pairs.
5. Oil cleanliness maintenance: Install a 10μm return-line filter in the hydraulic circuit. Replace hydraulic oil and all filter elements after the first 200 working hours, and periodically check oil contamination to prevent premature pump wear from solid particles.