How often to change an air dryer cartridge depends on how hard you work your air system. One US truck dealer says to replace it every one to two years.
The air dryer sits between the compressor and the air tanks. Its cartridge traps water and oil before they reach your brakes. Wet air can freeze or rust brake valves.
One air brake maker’s chart says 24 months for most line haul and delivery trucks. Trucks that use more air drop to 18 months, and severe duty to 12 months. Your truck maker’s schedule comes first, and it may be shorter.
Replace it sooner in these cases:
- A worn compressor: it can wear out the cartridge sooner.
- Tough weather: humid, dirty or freezing conditions are harder on it.
- Water in the tanks: more than normal condensation.
- Odd purging: the purge valve spits air nonstop, or air builds slowly after start-up.
A low air warning or any brake fault means stop and have it checked before you drive. Our Surrey and Port Moody shops carry heavy duty parts. For the full list, read our heavy duty truck maintenance checklist.
Service desk The full guide
Heavy duty truck maintenance checklist: the full checklist, step by step.