How to Adjust New Electric Drum Trailer Brakes

Question:

How do you adjust and break-in new electric drum trailer brakes?

asked by: John

Expert Reply:

The first step that you will want to take is to jack the trailer up on properly rated jack stands. Make sure the trailer is suspended securely before replacing the brakes. Once you have your new electric brakes installed and the hub and drum mounted, you will want to move to the back of the brake backing plate. There should be a rubber plug at the bottom of the backing plate. Remove the plug and you should see the teeth of a star gear inside the brake assembly. This is the brake adjuster.

You will want to use a flat head screw driver or a brake adjustment tool like part # W80630 to turn the star gear. Rotate the wheel up until it becomes difficult to turn the hub and drum. Rotating the wheel up will press the brake shoes against the drum.

Once the drum becomes hard to turn, back the wheel off about 10 clicks or until you can spin the drum with a slight drag from the brake shoes. I have attached an installation video that shows this process for you to check out.

Next, you will want to hook up your truck and trailer, drive around and apply the manual override from your in-cab brake controller. This is the break-in period. You will want to start around 40 mph and use the manual override only to slow down the truck and trailer. You may need to do this 20 to 30 times without using the truck brakes. This will allow the brake shoes and magnet to seat into the drum.

After the first 200 miles it is recommended to adjust the brakes again. After that, you will want to adjust the brakes every 3,000 miles.

Another option would be to use self-adjusting brakes, however they are not available in all sizes. You will still want to go through the break-in process with the self-adjusting brakes to make sure the magnets and shoes seat properly in the drum.

If you can tell me the weight capacity of your axle, the bolt pattern of your brake mounting flange (4-bolt, 5-bolt or 7-bolt) and the size of the brakes (10 x 2-1/4, 12 x 2, etc.), then I would be happy to make a more specific recommendation for you. I have attached a link to all of our electric drum brakes for you to check out.