How to Adjust the Rear Drum Brakes With the Tires On
Unlike disc brakes, which are self-adjusting by their design, the drum brakes commonly utilized on the rear wheels of many vehicles do require an initial adjustment whenever new linings are installed and may require routine readjustments in cases where the self-adjusters aren't working properly. Adjustment of drum brakes is a relatively simple task that most home mechanics can easily learn to perform without even having to take the rear wheels off the vehicle. Drum brake adjustment with the rear wheels in place will, in fact, allow you to adjust them very accurately.
Other People Are Reading
Things You'll Need
- Hydraulic floor jack, or other safe jack
- 2 Jack stands
- Wood blocks, or equivalent, to chock the front wheels
- Flashlight or drop cord work light
- Small straight screwdriver
- Brake cleaner
- Penetrating oil, with wand
- Drum brake adjustment tool (also known as a "spoon")
Instructions
-
-
1
Place wood blocks, or the equivalent under the front tires, to serve as wheel chocks. Jack the rear of the vehicle high enough to obtain a comfortable work space beneath it. Adjust the two jack stands and place one on either side, under the axle housings for rear-wheel drive vehicles, or under the subframe for front-wheel drive. Rock the vehicle slightly to insure that it is solidly supported on the stands.
-
2
Locate the brake adjustment access opening on the rear of the backing plate. This is normally located at the bottom of the plate. Remove the rubber plug, if there is one present, using a small straight screwdriver.
-
-
3
Inspect the self-adjuster through the access opening, using a flashlight or work light. Spray it with brake cleaner. Insert a plastic wand into the spray head of a can of penetrating oil. Carefully spray the exposed adjuster threads, taking care not to get oil on the brake linings. Allow it to penetrate for a few minutes.
-
4
Insert a brake spoon into the access opening far enough to engage the teeth on the adjuster wheel. If the adjuster is working properly, it will only turn in one direction and you will hear a clicking sound as you turn the adjuster wheel.
-
5
Place one hand on the tire and slowly rotate it as you tighten the adjuster. Keep this up until you feel resistance on the rear wheel. When you feel a moderate resistance, stop. Repeat this procedure on the other wheel. Try to get the resistance on both wheels as equal as you can.
-
6
Remove the jack stands and lower the vehicle to the ground. Press the brake pedal. It should feel firm and solid. Start the vehicle, put it in reverse and slowly back up and stop a few times. This will even out the rear adjusters.
-
1
Tips & Warnings
A common straight screwdriver, of appropriate size, can be substituted for a brake spoon in some cases.
If you don't hear a noise when you turn the rear adjuster wheel, or it will turn in either direction, move it a few turns and observe the threads on the adjuster. They will get longer if you're adjusting the brake shoes outward, toward the brake drum. If they seem shorter, turn the adjuster in the opposite direction.
Some adjuster access openings will have a stamped metal cover which will have to be knocked out with an appropriate chisel and hammer in order to gain access. You can buy rubber plugs for the access opening at most auto parts stores.
Due to differing designs, some imported vehicles may have the access opening at the top of the backing plate. Inspect the backing plate carefully on these vehicles.
Some vehicles have no brake adjustment access opening at all. If you don't see a stamped or notched opening on the backing plate, you will be unable to perform the adjustment. Take the vehicle to an authorized dealer or other reputable brake repair shop.
Take care not to over-tighten the adjusters and lock a wheel up. Stop when you feel moderate resistance.
References
- Photo Credit 4 wheel drive image by Canakris from Fotolia.com
