25 03 50 Compressor Cylinder Head — Cummins compatible

What does a compressor cylinder head do?

A compressor cylinder head is the cast service part that closes off the top of an air brake compressor's cylinder block and carries the seats for the inlet and discharge valves. It holds the piston's compressed air without leaking, routes it out through the discharge port, and carries away part of the compression heat from the body. This component is vital for the reliable operation of pneumatic braking systems in heavy commercial vehicles.

Compatible vehicles and engines

This cylinder head is engineered to be compatible with Cummins engines such as ISX15, ISL9, ISC, ISB, and N series. It fits a wide range of heavy-duty applications including Blue Bird Vision, Ford Trucks L9000, Freightliner models like the M2 106 or FL70, and Peterbilt series such as 379 or 567. It also serves various Volvo, Kenworth, and International truck models to ensure consistent air pressure delivery.

Installation and maintenance

When replacing a cylinder head, technicians should verify the bolt hole pattern and discharge port thread types against the original component. Proper installation requires adherence to specific torque values to prevent gasket leaks at the sealing face. Regular inspection of the valve seats and cooling ports is recommended to maintain optimal pneumatic performance.

Troubleshooting and selection

Maintaining the cylinder head helps prevent common symptoms like low air pressure or brake lag caused by internal leaks or overheating.

OE cross-reference

25 03 50 (Compressor Cylinder Head) is the equivalent of the Cummins and WABCO OE numbers. This part directly replaces Cummins OE number 4089206. It also replaces WABCO OE number 9111539212.