4089206 Compatible Cylinder Head for Cummins QSB

What does a compressor cylinder head do?

This cylinder head is a critical cast service component that sits on top of an air brake compressor's cylinder block to seal the compression chamber. It functions by holding the piston's compressed air without leakage, routing it through the discharge port, and managing thermal loads during operation. By replacing only the head, workshop technicians can rebuild a compressor in place, ensuring the system maintains optimal air output and pressure stability.

Engine compatibility and fitment

This specific part is engineered for compatibility with Cummins QSB engines. It is also suitable for other Cummins engine series including ISX, QSX15, ISC, L, M, ISB, and N. These components are essential for maintaining high-performance pneumatic systems in heavy commercial vehicles and construction machinery.

Installation and maintenance guidance

When performing a rebuild, ensure all valve seats and internal air passages are inspected for debris. Proper installation of the cylinder head is vital to prevent pressure drops or overheating within the compressor assembly. Maintaining correct torque specifications during assembly helps ensure the long-term integrity of the compression chamber.

Selection and troubleshooting

Check the compatibility list to ensure this part matches your specific engine configuration.

OE cross-reference

25 03 50 (Compressor Cylinder Head) is the equivalent of the Cummins OE number. This part directly replaces Cummins OE number 4089206.