When servicing wheel brake parts, do not create dust by cleaning with a dry brush or with compressed air. Asbestos fibers can become airborne if dust is created during servicing. Breathing dust containing asbestos fibers can cause serious bodily harm. To clean away asbestos from brake surfaces, use an OSHA-approved washer. Follow manufacturer's instructions when using the washer.
Several different methods are used to mount the drum to the wheel hub flange.
- It can be fastened with rivets or by swaging the piloting shoulders of the wheel studs, or with speed nut fasteners installed over the threads of the wheel studs.
- The most common mounting method is to use the tire rim and lug nuts. The drum is a slip fit over the axle flange and studs. Speed nuts are installed at the vehicle manufacturing plant for temporary retention of the drum on the assembly line until the wheel is installed.
- A floating drum can be retained by a nut and cotter pin. The drum can also be secured to the axle flange by one or two bolts. Some import applications have two additional holes threaded into the drum face so bolts can be used to press the drum from the hub or flange.
- After removing the retaining devices that hold the drum to the axle flange or hub, the drum can be removed for servicing.
- If the brake drum is rusted or corroded to the axle flange and cannot be removed, lightly tap the axle flange to the drum mounting surface with a plastic mallet.
- Remember that if the drum is worn, the brake shoe adjustment has to be backed off for the drums to clear the brake shoes.
- Do not force the drum or distort it. Do not allow the drum to drop.
- If the brake shoes have expanded too tightly against the drum or have cut into the friction surface of the drum brake, the drums might be too tight for removal. In such a case, the shoes must be adjusted inward before the brake drum is removed.
- On most cars with self-adjusting mechanisms, reach through the adjusting slot with a thin screwdriver (or similar tool) and carefully push the self-adjusting lever away from the star wheel a maximum of 1/16 inch (1.5 mm).
Backing off the self-adjusters in order to remove the drum brake.
- While holding the lever back, insert a brake adjusting tool into the slot and turn the star wheel in the proper direction until the brake drum can be removed.