Releasing trailer brakes

The system needs constant air once charged. The brakes will set again once you detach. Tell the trailer owner to cage the cans to release the brakes. No need for air.

 

You can just uncage them with a socket. Inside the brake chambers. Pop open the plastic plug in the middle. Google it. Everyone should know how. I've had to do it twice. Busted a brake airline twice.

 

Trailer supply line needs to stay charged with air or the trailer park brakes will stay set.

 

If they have been sitting for that long very possible the shoes are stuck to the drums also.

 

Applying air to red releases brakes, blue applies them. Just supply the red side.

 

Both pressured at the same time? No. The park brakes would release but the service brakes would be applied.

Just pressure up the supply line.

 

Call a mechanic.