AIR BRAKE COMPONENTS

Air Brake Components For Peterbilt Trucks

The air brake system is the backbone of stopping power on any Class 8 Peterbilt truck. Every component in the system — from brake chambers and slack adjusters to relay valves and air dryers — needs to function correctly to keep you safe and in compliance with FMCSA regulations. We carry a full range of air brake components for Peterbilt trucks so you can address issues quickly and minimize downtime.

Frequently asked questions about air brake components

What are the most commonly replaced air brake components?

Brake chambers, slack adjusters, and brake drums are among the most frequently replaced parts. Air dryer cartridges, relay valves, and gladhand seals also wear out regularly and should be inspected during every PM service. Keeping spares on hand can prevent roadside delays.

How do I know if a slack adjuster is out of adjustment?

With the brakes released, the pushrod stroke should be within the manufacturer's specified range — typically under two inches for most brake chambers. If the pushrod travel exceeds the limit, the slack adjuster may be worn or the automatic adjustment mechanism may have failed. Excessive pushrod stroke is a common out-of-service violation during roadside inspections.

How often should the air dryer cartridge be replaced?

Most manufacturers recommend replacing the air dryer cartridge every 12 months or 100,000 miles, whichever comes first. However, if you notice excessive moisture in the air tanks or the air dryer is purging more frequently than normal, the cartridge may need to be changed sooner.

Other parts you might need

Shop all brake parts for Peterbilt trucks