Trailer Brakes Question

Spring brake maybe? Do they set and hold firm after the air exhausts?

 

Does it charge fast then exhaust slow? Sounds like a hose fish gilling . That's a hose coming apart inside , it acts like. Trap door, allows flow in one direction( pushes out of way ) . Then when flow is in the other way it gets pushed down blocking flow. Or sticking air valve?

 

I would charge the trailer with shop air attached to glad hand with a valve. Close the valve, disconnect the air line, then open the valve and see if the trailer parking brakes apply normally, or slow. That way you know the problem is with the truck or trailer. ( you can simply pull of the red line while charged, but this can be dangerous and lead to injury). If the trailer is slow it may be just a sticking relay valve or quick release valve.

 

Sound like the quick release has given up the ghost.

 

I pull numerous trailers here in the north during the long cold winters. one trailer will do as you describe and the next hook will be fine . So I would definately say it`s the trailer. Depending on temps where you are it could be just freezing up abit or like others have said a valve going bad.