Time to sort out some confusion IMHO.
Looks like we have the OP jornvango and a second question posted by liltgeezer and one has a drum brake based question? and litlgeezer has a disc brake based question.
litlgeezer, you might want to start your own thread specific to your question and brake type. Us EOH rigs are the minority.
If you have any history on the trailer as far as axle and any brake related repairs or replacements, that certainly might help.
I have done more on my EOH than I bargained for, and I feel pretty comfortable outside some internal actuator troubleshooting.
Your disc brakes have an actuator to create pressure, lines, calipers with pistons (mine are 4 piston/caliper set for a total of 16 pistons) brake pads and rotors.
In function with the exception of the method of creating the pressure, they function much like any car or truck that has fixed rather than floating calipers. Fixed calipers have pistons on both sides, floating I think only has pistons on one side.
With your actuator not running, you should have ZERO PSI in the lines, much has been posted about the brake line routing and a current recall exists for short hoses. Are your lines long enough to allow for axle arc swing? If you have a single brake or even a single side getting hot and wearing down or burning up a pad. Here's an idea for diagnosing. Raise the offending wheel, spin the tire just to get a feel for the drag. Have someone manually apply the brakes, can't turn it right? Now release the brakes, still dragging? The pads do not have a return spring the pistons just stop applying pressure and allow the pads to relax and go to a normal slight drag. But if you are feeling a lot of drag, you could just open a bleed screw and observe if any fluid SPRAYS out, this would be residual pressure and might need more investigating. The possibility of residual pressure would affect ALL pistons, not an individual pad unless line crimped, kinked or internal delamination) But if no fluid sprays out, the system is at ZERO PSI which is the correct observation, then I'd be thinking a lot about possible sticking pads on the caliper housings and pin (all assumed that your caliper is like the ones I've worked with) and the big possibility that the pistons are dragging in the caliper bore from RUST.
If your dust seals are chewed up, water gets in, rust starts between the steel piston and cast iron housing. The system PSI forces the piston out, braking is created. BUT when you release the brakes, the rust prevents the pistons from relaxing and the pad(s) drag.
It happened to me on a virtually new axle/brake set. The lady at a toll plaza asked me if my tires were supposed to be smoking, they were'nt, it was an 800 degree plus rotor and pad set smoking away, but why just one axle? Rust.
If this is what happened, good chance you can fix it if you're handy. But this is a early possible diagnosis. I redid the piston seals and boots (really long story) a while back and with the finished repairs, I feel that I have 1st class brakes. I have lots of pic's.
2005 Dodge Ram 2500 5.9L 6 Speed
16" Michelins, Hi Spec Wheels, Max Brake, Carslile Actuator, Equal-i-zer, Dill TPMS. Campfire cook.