93 FLD 120. Non abs. Auto slacks (yes that was an option back then). I have an intermittent air leak when I apply the service brakes on the tractor. Occasionally when I apply the brakes, there will be a pulsating whoosh....like I'm repetitively applying and releasing the brakes. I replaced one air can that had a small leak, problem the same.
Would this be the relay valve not seating correctly? Could it be the proportioning valve? Or could a bad pancake from one of the other cans causing the problem?
I had a similar issue on an ABS Western Star a few years ago that ended up being the relay valve.
Any input would be appreciated
Pulsating air leak when service brake applied
Discussion in 'Freightliner Forum' started by ghalvie, Apr 30, 2020.