Electric Trailer Brakes According to Dexter AxleThe magnets physically wear out as they do their work. The brakeshoes press against the outer part of the drum but the magnets get sucked against the vertical part of the drum. The harder the braking, the more the magnets wear. When you replace the shoes, replace the magnets too. May as well replace the whole backing plate and be done with it. Checking the current they draw checks their electric worthiness but checking their thickness is also a must. If they're wearing unevenly, replace them. Dexter knows electric brakes read through their manual.
Don Ford
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