The spring brake (or multi-function) valve (18) limits the air pressure used to keep the trailer parking brakes off and, by means of an integral check valve, isolates a failed reservoir, which ...

This emulsion can clog and corrode brake system valves and air lines, ... serves as a check of dryer function and should be done at least every 25,000 miles, ...

Bleeding your car's brakes is vital for maintaining their performance so you are safe on the road. If you want to do it ...

Air dryers then condense and remove ... from the secondary reservoir through the secondary portion of the dual-control foot valve to actuate the front axle brakes. A two-way check valve senses the ...

If drivers find air reservoirs are not pumping back up to their full pressure following brake applications, there may be a problem caused by a faulty air dryer cartridge or canister.

Valve Replacement. If you do find it’s time to swap out a valve, you begin with the air system maintenance basics, chocking the wheels so the vehicle doesn’t roll, and draining the air system ...

Enter the cab, apply the brakes and observe whether air is escaping from the service line gladhand. The vehicle fails this test if air escapes from the disconnected blue service line. Spring brakes.

Check for system leaks, an inadequately sized compressor for the application, air-dryer purge valve stuck open, or a defective compressor unloader mechanism and/or governor. by Jim Park Jim Park was a ...