releasing brakes

I am sure you tried reversing the way the air lines are hooked up to the trailer.

 

Last time that rubber seal leak on me, it was because the trailer was somehow pushing the air though the blue line. Not sure if that would help

 

unhook the glad hands, push the red button in momentarily, you should hear a rush of air from the lines. Pull the red button out. hook up only the red line, push the red button in, check for air back feeding from the blue line, if the blue line is back feeding either you have a bad trailer valve or brake pot leakage, if you suspect brake pot , crawl under the trailer (with the tractor brakes locked and the wheels chalked ) and see if you can hear any air leakage. if nothing is obvious, start removing the service lines at the brake pots or the pot side of the valve which ever is easier. if you find air coming from a pot service port. replace that pot. if you don't have any back feed from any of the pot service ports, verify that you have good flow to the emergency side of the trailer valve (red line) if so replace valve. You can try adding airbrake antifreeze to free up a stuck valve, but is a roadside break down for the same problem worth the cost of the valve. I recommend new valves or remans from the original manufacturer only.

 

Excellent troubleshooting guide! If they can't figure it out by following this, they need help.

 

Swap the glad hands on the trailer, or repaint them accordingly.