One Brake Sometimes Locks Up on a 5th Wheel Trailer

Question:

The left front wheel sometimes locks up. This had happened a few years back, so I rewired the brakes with heavier gauge wire to ensure all brakes received the same voltage. This wheel is the first on the circuit. This obviously helped since the full amps for all 4 brakes increased after completion and the brake no longer locked up. Now the problem has returned and I think it may be because the magnet has worn more than the others and became stronger if the coil has come closer to the drum. Is my theory sound and are there other reasons for one wheel to lock up? My brake controller has an ammeter and the reading looks normal.

asked by: Lynn F

Expert Reply:

Often times when one brake locks up and the others do not it is an electrical issue that can stem from several sources. First you will want to visually inspect the magnets to see if the windings are coming through. If they are then the magnets will need to be replaced. They could be shorting out and drawing too much power causing it to lock up.

Another issue could be the wiring to the magnets. Make sure the grounds are attached to a nearby corrosion free bare metal surface. Inspect the power wires for any nicks in the wiring that may be touching bare metal on the trailer as that can cause a short as well.

To further test the magnets I have included a link to an FAQ that you can follow.

If the nearest brake continues to provide more aggressive braking than the others you may need to back off the adjustment a little on that one assembly to compensate.

expert reply by: Michael H