At a minimum, Bendix recommends draining the air reservoir and checking for moisture in the system every 25,000 miles, three months, or 900 hours under standard air usage conditions; every 12,000 miles, two months, or 450 hours for medium air usage; and for heavy air usage vehicles, every 6,000 miles, one month, or 300 hours. 

 See Bendix Air Dryers and Cartridges in our Winter flyer! 

 Replacement intervals also depend on the type of cartridge: A standard OEM-grade cartridge, an oil-coalescing cartridge, and an aftermarket replacement have different performance expectations.   

Bendix’s new service intervals were created with its own specific dryers – its standard cartridge; the PuraGuard® oil-coalescing cartridge; and the Bendix® GC™ Green Cartridge – in mind.   

Check out this tool from Bendix: Recommended Service Intervals for Bendix® Air Dryers.  

Recommended Service Intervals   

For easy reference, Bendix categorizes vehicle air usage into three general levels: standard, medium, and high.   

Standard use: Five axles or fewer; line-haul; city; delivery should be replaced every 24 months or 200,000 miles.   

Medium use: Pulling double trailers; light transit; light off-highway; eight axles or fewer – should be replaced every 18 months or 150,000 miles.   

High-air-use: Such as multiple trailers, city transit, heavy-duty off-road, and nine or more axles should be replaced every 12 months.   

Vigilance is particularly key with oil-coalescing cartridges because of the specific job each medium has within the component: The oil filter doesn’t remove moisture, and the desiccant isn’t designed to remove oil – but both are crucial.   

Especially on newer trucks, oil-coalescing filters are protecting components that can carry a significant repair cost. If your truck was originally equipped with an oil-coalescing cartridge, it’s important to replace it with one. And you can always upgrade from a standard cartridge to an oil-coalescing version, even if it’s not OEM spec: It’s just an added level of protection.  

For OEM-grade standard Bendix cartridges without oil-coalescing technology, the recommended standard/medium/high usage replacement intervals are 24, 18, and 12 months, respectively.   

For the Bendix® GC™ Green Cartridge, which is intended for older trucks and uses a proprietary mix of new and Bendix-remanufactured desiccant, recommended replacement intervals are 12 months for standard and medium usage, and six months for high.