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Section 3
Mechanical Brakes
Disassemble DCM Brake
WARNING
To prevent serious eye injury, always wear safe
eye protection when you perform vehicle
maintenance or service.
WARNING
Block the wheels to prevent the vehicle from
moving. Support the vehicle with safety stands.
Do not work under a vehicle supported only by jacks.
Jacks can slip and fall over. Serious personal injury
can result.
1. Make sure the vehicle is on a level surface.
2. Place blocks under the wheels not being
serviced to keep the vehicle from moving.
3. Raise the vehicle so that the wheels to be
serviced are off the ground. Support the
vehicle with safety stands.
4. Disconnect the drive shaft using standard
procedures.
5. Release the brake.
6. Remove the brake drum using standard
procedures
7. Remove the nut and washer that hold the cam
to the lever.
8. Remove the cam and the lever.
9. Use a brake shoe return spring removal tool
to remove the two or four brake shoe return
springs from the ends of the brake shoes.
Discard the springs and replace them with
new springs at assembly.
10. Remove both brake shoes and mark them to
identify their original position at assembly.
11. Remove the actuator strut.
NOTE: Make a note of how the brake backing plate is
mounted. Use the position of the cam as the reference
point.
12. If complete disassembly is necessary, remove
the four brake backing plate capscrews and
washers.
13. Clean and inspect all parts. Refer to Section 4.
DCM Brake
(Duplex Cam Mechanical)
Description
The DCM brake is a two shoe mechanically
actuated brake. The brake is available in 10" x 3"
(254 mm x 76.2 mm) and 12" x 3", 4" and 5" (304.8
mm x 76.2 mm, 101.6 mm, 127 mm) sizes.
Figures 3.1 and 3.2.
WARNING
Some brake linings contain asbestos fibers, a cancer
and lung disease hazard. Some brake linings
contain non-asbestos fibers, whose long-term
effects to health are unknown. You must use
caution when you handle both asbestos and non-
asbestos materials.
