Flatbed Trailer no brake release and no air bag inflation

reverse the glad hands , may be hooked backword on trailer , some trailers are .

 

I had a stepdeck pull that #### on me earlier in the year...I'll be ###### if I remember what it was though.

 

Spring brake valve? Would keep brakes and suspension from airing up.
Sealco Commercial Vehicle Products - Spring Brake Valves

 

If it’s coming from the discharge port in the middle in the bottom it’s probably a bad valve. The leveling valve has nothing to do with the relay valve. If it leaking bad enough the tank isn’t building enough air to overcome the crack pressure on the regulator.

 

If he’s been pulling the trailer that wouldn’t make any sense.

 

Sometimes if the shaft seal between the emergency side and service side of a brake chamber is leaking, it can send back pressure to the full function valve and cause it to bypass air just like you're describing.

It will bypass so much air that the air tank on the trailer will never reach the 60 to 90 psi to overcome the inversion valve or check valve to send air to the leveling valve or release the brakes.

I'd take a c clamp and block off the emergency side of each brake maxi 1 at a time to rule out a bad brake chamber.

 

I carry a set of needle nose vice grips just for pinching lines.

 

Those make doing that so much easier for sure man.