Bendix Commercial Vehicle Systems DOUBLE ANCHOR PIN CAM BRAKE 5/04 - Manual (Page 5)

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DISASSEMBLY (See Figure 2)
1. Insert a sturdy lever between one of the shoes and the
cam shaft housing. Pry shoe away from cam roller until
pin and roller assembly can be removed. Repeat on
opposite shoe (See Figure 3). (If cam rollers or pins show
signs of wear, galling, pitting or cracks, discard and
replace with new.)
2. Remove shoe return spring and discard. Force shoes
towards the S-cam to relieve spring tension (Figure 4).
3. Remove shoes. Lift one of the shoes off anchor pin and
lower both shoes to the floor (see Figure 5).
4. Remove the two shoe retainer springs and discard. NOTE:
If only replacing the brake shoes, no further disassembly
is required. Reverse Steps 1 thru 4. NOTE: Always install
new springs.
5. Remove the two anchor pins by sliding them out of the
bushings. If bushings are to be replaced, drive them
out of the spider using a tool of the proper diameter (a
15/16" socket will work as a driver).
6. Remove the cotter pin from the yoke of the actuator.
Remove yoke pin so the slack arm is free of the yoke.
Remove the two nuts and washers that secure the
actuator to the bracket and remove the actuator.
7. Remove snap ring and washer from splined end of cam
shaft. Remove slack adjuster from cam shaft. (A puller
may be required.) Remove spacers and the thick washer
from cam shaft (See Figure 6).
8. Remove cam shaft from actuator bracket and cam tube.
Remove large flat cam head washer from the cam shaft.
9. Mark and remove the dust shields from the spider by
removing the six cap screws using a 3/8" socket. Do
not remove unless there is apparent damage.
10. Remove the actuator bracket and cam tube from the
spider by removing the four cap screws and lockwashers
using a 3/4“ socket. Remove and discard the sealing
gasket from the end of the actuator bracket (See Figures
2 and 7).
11. Remove and discard the two cam shaft grease seals.
One at the end of the actuator bracket and one at the
cam entrance in the spider. Pry out with a large
screwdriver.
12. Remove the spider from the axle flange by removing
the twelve bolts, nuts, and lockwashers that secure it.
To facilitate assembly, note or mark the relationship of
the spider to the axle (driver or curb side) and the
orientation on the axle flange.
13. Remove and discard the two cam shaft bushings located
in the same area as the seals in Step 11. Use a drift of
adequate length to drive the bushings out. NOTE: Prior
to removal, see the “Inspection of Parts” section, Steps
1B and 3B.
CLEANING OF PARTS
After disassembling the foundation brake, Wash the metallic
components in mineral spirits and wipe dry. Be careful not
to get any foreign material, especially grease on the brake
shoes or interior of the brake drum. Use a wire brush to
remove heavy contamination from the spider and outside
of the brake drum.
INSPECTION OF PARTS
1. ACTUATOR BRACKET AND CAM TUBE
A. Check assembly for bent actuator bracket and broken
or cracked cam tube welds.
B. Inspect cam shaft bushing for signs of wear. Bearing
surfaces should be smooth and free of any pitting or
fractures. Insert cam shaft and measure looseness
at both ends with a dial indicator. If more than .020"
movement is noted, replace bushings and/or cam
shaft. NOTE: If it is determined that a bushing
requires replacement, both cam shaft bushings
should be replaced.
2. CAM SHAFT
A. Inspect cam shaft spline for cracks and excessive
deformation. Replace as necessary.
B. Inspect the cam shaft bearing journals for wear or
corrosion. If the shaft shows wear or roughness that
is visible or roughness that can be detected by feel,
it must be replaced.
C. Inspect cam head for cracks, and its roller surfaces
for flat spots, brinneling, or ridges. Note unusual wear
patterns which may indicate an out-of-square
condition. Replace if any of these conditions exist.
3. SPIDER
A. Inspect for cracked or broken surfaces an the spider
at the cam, anchor pins, and mounting bolt holes.
Replace any spiders with visible damage. Do not
attempt to weld or repair. Check fit of anchor pins in
torque spider. Radial clearance in excess of .010"
indicates excessive wear. Replace anchor pin
bushings and/or anchor pins.
B. Check cam shaft bushing for signs of wear. (See 1
B) Bearing surface should be smooth and free of
any pitting or fractures. NOTE: If it is determined
that the bushing requires replacement, change both
cam shaft bushings.
4. ROLLERS AND PINS
A. Inspect rollers and pins for flat spots, galling, broken
or cracked surfaces. Replace as necessary.
5. ANCHOR PIN
A. Inspect anchor pin for worn, broken or cracked
surfaces. Replace as necessary.