Trailer Brake Drums are Discolored and Brakes are Smoking

Question:

I have 10inch x 2.25 brake drums on a 2005 Shadow 3 horse slant aluminum horse trailer. Ive noticed that the armature surface is wavy but it doesnt appear that the magnets are matching wavy. Obviously the braking is lessened when the magnets dont have full surface contact. Question - is it reasonable to have the armature surface turned and reuse the magnets? Secondly - the drivers side backing plate and components are extremely sooted. Even under the wheel well is sooted. Cars following the trailer have motioned that the brakes are smoking. When testing however, the magnets grab and release appearing to operate normally. Any idea what is causing the smoking and soot. By the way, the bearings are packed properly and show no sign of overheating however, the brake drums where the shoes hit are spotted with dark marks like a Dalmation dog. Indicates excessive heat most likely. Brake lining has around 1/8inch lining.

asked by: Garry H

Expert Reply:

If you are noticing discoloration on the inside of the drums then that is an indication that there is excessive heat like you said. Make sure that the spindles are also well greased since heat can transfer from there and not just the bearings. The only way to correct this issue so that the brakes will function normally is to replace the hub and drum assemblies. I would just need to know the inner and outer bearing numbers and the bolt patter of your hubs to make some recommendations.

The brakes might have been adjusted too aggressively. You will want to adjust them to where you can hear a slightly but constant drag of the pads on the inside of the drum.

Something else that could cause braking problems is if the brake assemblies are not lined up right with the drum. This could happen if the brake mounting flanges where not welded on perfectly straight and concentric. Or if something was damaged from impact or overloading the trailer, that could cause problems as well.

expert reply by: Michael H