495-7571 Cat Piston Pump D8R 140cc 3600psi

Product Overview

The 495-7571 (4957571) is the main hydraulic pump assembly (PUMP GP-PISTON) for the Caterpillar D8R and D8T Track-Type Tractors (bulldozers). This swashplate-type axial piston variable displacement pump delivers reliable high-pressure oil supply for blade control, steering response, and attachment hydraulic systems.

The 495-7571 is compatible with the following Caterpillar cross-reference part numbers, allowing customers to select based on inventory and procurement preferences:

• 112-7913 (1127913) — PUMP GP-PISTON – HYDRAULIC FAN

• 9T-1211 (9T1211) — Fits CAT 446/446B Backhoe Loaders

• 7J-2194 — Fits CAT D5 Dozers

• 6E-6562 (6E-6563) — Fits CAT 5230/5230B Excavators

• 259-0814 (2590814) — Fits CAT 345C/345CL/W345C Excavator Fan Pump

As a direct OEM-equivalent replacement solution for the Caterpillar 495-7571 main pump, this product offers complete in-situ interchangeability, strictly adhering to Caterpillar’s original design specifications and mounting interface standards. Every unit undergoes 100% simulated duty-cycle testing, ensuring that key performance metrics—including volumetric efficiency, pressure-flow characteristics, and case drain flow at rated pressure and full displacement—meet or exceed original factory specifications.

Technical Specifications 

• Model Number: 495-7571 (4957571)

• Brand Series: Caterpillar D8R / D8T Track-Type Tractor

• Pump Type: Swashplate Axial Piston Variable Displacement Pump

• Displacement: 140 cm³/rev

• Rated Working Pressure: 3600 PSI (approx. 248 bar)

• Maximum Input Speed: 2000 RPM

• Control Type: Pressure Compensator Variable Control

• Mounting Type: OEM Standard Flange Mounting

• Housing Material: High-strength Cast Iron

• Design Features: Compact design, low noise level, sealed shaft bearing

• Applicable Models: Caterpillar D8R / D8T Track-Type Tractors

• Cross-Reference Part Numbers: 112-7913 / 9T-1211 / 7J-2194 / 6E-6562 / 259-0814

• Weight: Approx. 160 kg

Key Technical Advantages

1. Dozer-Specific Main Pump Design for Heavy-Duty Applications
The 495-7571 is the dedicated main pump assembly for Caterpillar D8R/D8T Track-Type Tractors, delivering stable and reliable hydraulic power output for blade control, steering, and attachment systems. The high-strength cast iron housing withstands severe vibration and pressure spikes common in dozing operations.

2. 140cc Large Displacement with 3600 PSI High-Pressure Rating
The 495-7571 delivers 140 cm³/rev displacement with a rated working pressure of 3600 PSI (approx. 248 bar) . With a maximum input speed of 2000 RPM, it outputs ample hydraulic power to meet the demanding requirements of D8R/D8T large dozers in heavy ripping and dozing applications.

3. Compact Design with Low-Noise Operation
The 495-7571 features a compact structural design for easy installation and maintenance within the D8R/D8T’s confined engine compartment. Low-noise operation improves operator working conditions, while the sealed shaft bearing prevents external contaminant ingress, extending pump service life.

4. Broad Cross-Reference Compatibility
The 495-7571 is compatible with multiple Caterpillar part numbers including 112-7913, 9T-1211, 7J-2194, 6E-6562, and 259-0814. This broad cross-reference coverage enables customers to select based on existing inventory and procurement channels, effectively reducing parts management complexity and procurement risk.

5. Proven Axial Piston Design
The 495-7571 features a proven swashplate axial piston variable pump design with high volumetric efficiency, low internal leakage, and excellent self-priming capability. The rigorously validated rotating group and high-precision friction pair design ensure long-term reliability under continuous high-load operating conditions.

Application Areas

• Caterpillar D8R Track-Type Tractor (Primary Application): Main hydraulic pump providing power for blade lift/tilt and steering systems

• Caterpillar D8T Track-Type Tractor: Main hydraulic pump assembly

• Caterpillar D8 Series Dozers: Maintenance and replacement applications

• Heavy Construction Equipment Hydraulic Systems: Applications requiring 140cc displacement and 3600 PSI pressure rating for track-type equipment

Expert Maintenance Tips

1. Model Confirmation & Pre-Installation Inspection: Prior to installation, confirm the equipment is a Caterpillar D8R or D8T Track-Type Tractor and verify the original pump part number is 495-7571 (4957571) or one of its cross-references (112-7913 / 9T-1211 / 7J-2194 / 6E-6562 / 259-0814). The pump weighs approximately 160 kg—ensure lifting equipment has adequate capacity. Manually rotate the shaft before installation to confirm smooth, obstruction-free rotation.

2. Fluid Cleanliness Control: Use high-quality hydraulic oil meeting Caterpillar specifications with a minimum filtration rating of ISO 18/15. D8R/D8T dozers typically operate in high-dust environments—complete system flushing is mandatory before initial start-up.

3. Pressure Compensator Tuning: The 495-7571 features pressure compensator variable control. Set the compensator pressure value according to the Caterpillar D8R/D8T Service Manual. Perform initial settings under no-load conditions, then gradually increase load to target pressure (3600 PSI) with fine adjustments.

4. Initial Start-Up & Priming: Before first start-up, pre-lubricate the pump by filling the housing with clean hydraulic fluid through the case drain port. Perform a brief jog start (5–10 seconds) to check for abnormal noise, leakage, or excessive vibration. Then正式 start the pump and run at low load for several minutes to purge air from the pump and system lines.

5. Case Drain Port Positioning & Pressure Monitoring: During installation, ensure the drain port is positioned higher than the pump body to prevent oil starvation in the pump chamber after shutdown. Install a pressure gauge on the case drain line for real-time monitoring to ensure case pressure remains within specifications.

6. Scheduled Maintenance & Filter Replacement: Follow the maintenance intervals specified in the Caterpillar D8R/D8T Service Manual. Pay particular attention to filter condition, fluid cleanliness, and seal integrity during routine inspections. Regular hydraulic fluid and filter replacement is essential for long-term reliable pump operation.