Only the Left Side Trailer Brake Locks Up using a Time Delay Brake Controller

Question:

I have a electric brake system now, but on the last trip the brake controller had to be adjusted to the absolute lowest power to keep the left rear tire from locking up. then, whenever I back up, the left rear locks up completely. Im thinking about your proportional controller to eliminate any controller problems. Also Im wondering if I need to replace the wheel brakes too. I have 15 trailer wheels, do I need a 10 brake drum assembly. I want to order whatever I need today. Please let me know.

asked by: Steve

Expert Reply:

First, since only the left side was locking up, there could be a problem with the brake and/or wiring on that side. You will want to check that the wiring is intact with no cuts, breaks, or nicks. Also make sure that the ground is attached to a clean and corrosion free bare metal surface.

If the brake or wiring is not in working order, a new brake controller would not help. However, I do recommend a proportional controller over a time delay controller because they are the safer way to apply trailer brakes. I have included a link to an FAQ article covering brake controllers.

Further testing of the brakes could show that you may only need to replace a magnet. You can visually inspect the magnet first. If you see the windings coming through it is time to replace the magnet.

You can also test the magnet for electrical problems to determine if it has gone bad. I have included a link to an FAQ article that explains how to check the magnet using a multimeter like # BTMT15.

To replace an entire brake assembly I would need to know the axle capacity and the measurements of the old assembly including the mounting hole pattern. With a 15 inch wheel I would think you have 12 inch assemblies. When replacing brakes you should change out both sides at the same time instead of just one.

expert reply by: Michael H