204-2578 SN83335345 CAT Axial Piston Pump D8R D8T

Product Overview

Part number 204-2578 (serial SN83335345, also known as 2042578 / CA2042578) is a Caterpillar hydraulic axial piston pump group (Pump GP-Piston) designed for the hydraulic system of D8R / D8T track-type tractors. The unit offers 100% drop-in interchangeability with genuine CAT pumps—no piping or mounting modifications required. Every unit undergoes full simulated operating-condition testing to guarantee reliability and stable performance under heavy-duty loads in main hydraulic or fan-drive circuits of construction machinery.

Technical Specifications 

• Model: 204-2578 / 2042578 / CA2042578 / SN83335345
• Type: Axial piston pump (Hydraulic Axial Piston Pump / Pump GP-Piston)
• Compatible machines: Caterpillar D8R, D8T bulldozers / tractors
• Related engines: C15, 3406
• Weight: approx. 41.6–41.9 lbs (18.9–19 kg)
• Design features: OEM-specification axial piston construction for high-pressure hydraulic system requirements

Key Technical Advantages

1. Precision-machined axial piston rotary group ensures stable flow and high volumetric efficiency under high pressure.
2. Materials and bearings optimised for the heavy-duty operating conditions of D8R/D8T deliver long service life and shock resistance.
3. Exact match to original mounting dimensions, shaft spline and port interfaces enables true drop-in interchangeability and eliminates modification costs.
4. 100% full operating-condition testing verifies pressure, speed and sealing performance for reliable out-of-the-box operation.
5. Fully compatible with CAT hydraulic circuit and control logic, simplifying maintenance and reducing downtime.

Application Areas

Designed for the hydraulic system (main pump or fan pump) of Caterpillar D8R and D8T track-type tractors, as well as similar large earthmoving machines equipped with C15 or 3406 engines.

Expert Maintenance Tips

1. Before installation, verify the part number and serial number; confirm exact match of mounting flange, shaft spline and inlet/outlet ports with the original pump.
2. Fully bleed the system before first start-up. Use hydraulic fluid meeting CAT specifications and maintain system cleanliness.
3. Periodically inspect for case leakage, temperature and pressure; monitor the condition of filters in the fan or main circuit.
4. When changing filters and oil, inspect the pistons and valve plate for wear. Perform preventive maintenance if flow decreases or abnormal noise appears to maximise hydraulic-system longevity.