This document describes the break-in procedure for electric drum brakes. The break-in period is a typical
phenomenon with drum brakes and especially electric drum brakes. Electric drum brakes will require a break-in
period to achieve full performance. This break-in period applies for new axles and any time new brake shoes and/or
magnets are installed as part of regular maintenance. This break-in period not only seats the shoe lining material but
also seats in the brake electro-magnets. During the break-in period, the linings will wear at a faster rate than they do
after they are seated in
Follow this procedure and you will seat the brakes on the drums
So the basics are:
- Standard Burnishing Procedure
This method utilizes a lower speed. However, a minimum of 40 mph is required for burnishing of the brakes.
NOTE: This method will need 20 to 50 brake applications. Brakes can be seated in by applying approximately 8-10
volts to the trailer brakes at an initial speed of 40 mph and allowing the tow vehicle/trailer combination to slow down
to 20 or 25 mph.
- Proceed at driving speeds up to 40 mph. (Make sure there are no other cars behind you)
- Move the slide mechanism on the brake controller to apply 8 to 10 volts (Gain) to the trailer brakes, allowing the tow vehicle to slow down to 20 or
NOTE: For maximum effectiveness, do not use tow vehicle brakes or exhaust brakes during this period. The trailer brakes will seat in faster by using only
the trailer brake to stop both tow vehicle and trailer.
- Release the slide mechanism on the brake controller.
- Continue down the road applying the brake controller as detailed above at one-mile intervals. NOTE: Driver should feel a noticeable difference in
the brake performance during this period, sometimes in as few as 10 applications.
- Use best judgment to determine brake performance after 20 to 50 applications of the procedure. After brakes feel like they are well seated, pull
over at the next exit or any safe location to check the status of the procedure.
- The brake/axle area may be showing smoke from the procedure and the area around the brakes should be hot.
Perform all burnishing of brakes at posted speeds. Never do this on a busy road always think safety first.
1. Turn the GAIN on the trailer brake control to the maximum level.
Check hitch connection, electrical connections, sway bars and connect breakaway cable.
- If available, use a temperature gun to determine that temperatures are between 350 and 400 degrees, or verify that the area is hot with a hand
check. (Hold hand away from any metal just see if there is ambient heat)
- If there is no smoke or the heat has not achieved the proper temperature or the area can be touched with a hand, perform the procedure again as
- NOTE: If the brake drum is cold to the touch the brake drums may not be adjusted properly or there may be a wiring concern.
- NOTE: After 50 applications, the brake lining material will be fully cured from the heat and develop close to 100 percent contact with the brake drum surface.