: 277-5566 CAT Hydraulic Piston Pump for D6M Bulldozer

Product Overview

This is a direct OEM-interchange hydraulic axial piston pump (Pump GP-Piston) covering part numbers 277-5566 and 134-2947 (10R-0857). Engineered for Caterpillar D6M track-type tractors (bulldozers), it features a variable-displacement axial piston design integrated with a load-sensing hydraulic system. The pump delivers precise flow and pressure matching to work demands. Manufactured to exact OEM dimensions and interfaces for 100% drop-in interchangeability. Every unit undergoes 100% simulated operating-condition testing to verify performance, sealing integrity and reliability under demanding dozing and grading cycles.

Technical Specifications 

• Part Numbers: 277-5566 / 134-2947 (10R-0857)
• Pump Type: Variable Displacement Axial Piston Pump
• System Type: Load-sensing hydraulic system
• System Pressure: Approximately 248 bar (3600 psi)
• Pump Flow: Approximately 119 L/min (31.5 gpm)
• Control Method: Pressure and flow compensation (load-sensing control)
• Weight: Approximately 82 kg (reference aftermarket data)
• Compatible Models: Cat D6M Track-Type Tractor / Bulldozer (and related compatible machines)
• Other: SAE flange mounting, splined drive shaft

(Note: Exact displacement, peak pressure and maximum speed of the pump itself should be referenced from official Caterpillar service manuals in the SENR series. Data above is based on published D6M machine hydraulic system specifications and verified interchangeability.)

Key Technical Advantages

• Precision drop-in interchangeability: Mounting flange, shaft end and ports match OEM exactly for fast, no-modification installation and minimal downtime.
• Load-sensing variable control: Automatically adjusts displacement and pressure to actual demand, improving fuel efficiency, response and reducing energy loss.
• High-strength materials and precision manufacturing: Wear-resistant friction pairs and bearings combined with tight-tolerance machining deliver high volumetric efficiency and low internal leakage.
• 100% simulated duty-cycle testing: Full performance validation under rated pressure and flow conditions before shipment ensures sealing reliability and extended service life.

Application Areas

Implement hydraulic systems on Cat D6M track-type tractors (bulldozers). Ideal for road construction, land leveling, mining overburden removal, building foundation work, agricultural land clearing and other applications requiring efficient dozing and grading performance.

Expert Maintenance Tips

Clean ports and drive shaft thoroughly before installation. Use recommended hydraulic oil and verify system cleanliness. After replacement, run at low speed under no load, then gradually increase load while checking for unusual noise or leakage. Monitor oil temperature and filter condition regularly; avoid prolonged over-pressure operation. Perform pump flow and compensator valve pressure tests/adjustments according to the official Cat service manual to maintain system pressure within specified limits.