Trailer brakes locked up after sitting a couple months?

It won’t stop the shoes from rusting to the drums. That can happen in a day or two in some cases. But when you live in the land of dirt dobber ( dirt wasp) you should always store your trailers with sealed dummy gladhands on them to keep dirt and moisture out of the open lines.

 

Sometimes you can bang away at the drum and the brake shoes won't turn loose. I put the end of a crow bar against the metal part of the brake shoe and tap on it with a hammer. It doesn't take much force. Just a light tap. When the bottom shoe lets go the top one usually will also.

 

I'm still trying to wrap my head around how hooking the supply line to the trailer's service line is gonna blow anything out. Its a closed system. Service and supply are 2 seperate circuits.

 

I'm about 96% positive I've hooked em backwards before and had air coming out the other side. Hard to remember everything

 

About what the OP said, the same effect can be achieved by simply applying the service brakes at full power once the air tanks max out. The reason for waiting for the air tanks to max out is so there is a higher braking power. I’ve actually tested this out (by accident) while checking the slack in my slack adjusters. I suppose it’s possible to unstick some brake shoes by simply moving them up and down by releasing the brakes and applying over 100 psi of braking power several times.

 

That’s exactly what I do and it works all the time baaaaaaawqqqqqwm

 

Try brakes that have set for many years? Hammer, penetrating oil, tire irons, thin blade screwdriver,,,,,,,,,