3948842 QSB Single Cylinder Compressor

What does a single cylinder compressor do?

This single cylinder air brake compressor is a piston-type component that provides the essential compressed air required for the pneumatic braking systems in heavy commercial vehicles. It utilizes a water-cooled design to manage operating temperatures during high-load cycles, ensuring consistent pressure delivery to the air processing unit.

Engine compatibility and fitment

This compressor is specifically engineered for compatibility with Cummins engines, including the QSB, 6BT5.9, 6CT8.3, ISB, and C50 series. It is built to withstand the rigorous demands of heavy-duty service while maintaining precise air output through its specialized valve plate and through-drive configuration.

Technical specifications and installation

Technical specifications include a Ø75.00 mm cylinder bore and a 56 mm stroke, resulting in a swept volume of 247cm³. The unit features an M27x2 air outlet port, an M10x1 unloader port, and water inlet/outlet ports sized at 3/4 16UNF. Installation should be performed by a workshop technician to ensure correct alignment of the through-drive and secure connection of all fluid lines.

Maintenance and troubleshooting

Regular inspection of the water cooling lines and air ports is recommended to prevent system pressure drops or overheating. Maintaining clean intake air helps preserve the longevity of the internal piston and ring assemblies.

OE cross-reference

2500 090 001 (Single Cylinder Compressor) is the equivalent of the Cummins OE number. This part directly replaces Cummins OE number 3948842.