AIR COMPRESSORS

Air Compressors For Peterbilt Trucks

The engine-driven air compressor is responsible for building and maintaining air pressure across your Peterbilt's brake system, suspension, and accessories. When the compressor starts to fail, you'll notice slow pressure buildup, excessive cycling, or oil contamination in the air system — all of which can compromise braking performance and trigger costly downtime. We carry air compressors and related components for Peterbilt trucks powered by PACCAR and Cummins engines.

Frequently asked questions about air compressors

How do I know if my truck's air compressor is going bad?

Watch for slow air pressure buildup on the dash gauges, the compressor running constantly without cutting out, excessive oil in the air tanks or dryer, and unusual knocking or rattling noises from the compressor. Any of these symptoms warrant immediate inspection to avoid brake system failures.

What causes oil to pass through the air compressor?

Oil passing, also called oil blow-by, typically occurs when the compressor's piston rings or cylinder walls are worn. This allows engine oil to enter the air system, which can saturate the air dryer cartridge, contaminate brake valves, and reduce overall braking efficiency. Replacing the compressor and servicing the air dryer is the recommended fix.

Can a failing air compressor cause the truck to go out of service?

Yes. If the compressor cannot maintain adequate air pressure, the brakes may not release fully or apply properly, which is a critical safety issue and an automatic out-of-service violation during a DOT inspection. Low air pressure will also prevent the parking brake from releasing, leaving the truck immobile.

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