Troubleshooting New Trailer with One Brake That Locks Up

Question:

I have a brand new trailer. I keep having one trailer brake lock up when Im using my brake controller. I was trying to adjust my brake controller power per directions for the Prodigy RF. I drive on a flat surface at 20mph and use the manual override to engage the brakes. Even at a very low setting one wheel will lock up when I fully engage the manual override, the others work as they should and do not lock up. I thought that brake might be over-adjusted so I adjusted that brake per dexter specs but it did not make a difference. I then under-adjusted it so that the wheel spins freely without any resistance just to see what happens. It will still lock up when manual override is fully engaged, however it now does run at the same temp as the others after I under-adjusted. Any ideas? Its brand new so very unlikely its do to worn parts.

asked by: Steve

Expert Reply:

Use of the manual override on your trailer brake controller should not cause any different behavior from any of the brakes as compared to normal operation via the brake pedal. All of the brakes on the trailer should be receiving more or less an identical voltage from the controller since they are all wired together to one shared circuit. The controller itself cannot send more power to one of the four brakes.

If three of the four brakes on your new trailer operate correctly then I suspect that there is an issue with the one brake assembly, such as mechanical damage to the shoes or linkage that is allowing too much pressure to be applied to the drum surface, a problem with that one hub/drum or an electrical fault of some kind that is allowing another power source to reach the brake magnet. If you have a multimeter like # PT89ZR you can read the actual voltage at each brake to see if the power reach them is equal as it should be.

You can also try swapping the hub/wheel from the problem brake to another one on the trailer and see if the problem stays with the hub/wheel or if it remains on that same spindle location. If it follows the hub/wheel then I would suspect you have a bad hub; it is stay at the same spindle then I would suspect the brake assembly is bad.

expert reply by: Adam R