GMC 4000 Series Service Manual page 249

Sec. 5B
Page 242
AIR BRAKES
1 Retaining Cage
2 "Ears" on Washer
3 Roller
4 Wedge Retainer
Washer
Figure 3 4 — W ed g e and Roller Assem bly
CLEANING AND INSPECTION
All components should be thoroughly cleaned
prior to inspection and reassem bly.
1. Inspect wedge for bent or distorted condi­
tion. Examine bearing surfaces for scoring or
wear. Replace wedge if there is evidence of wear
or distortion.
2. Examine rollers for any wear or out-of-
round condition. No scratches or scoring is per­
m issible.
3. Examine wedge spring for fatigue or cor­
rosion. Replace spring if necessary.
4. Inspect actuation housing cylinder bores for
scores, scratches, or corrosion. Light scratches
or slightly corroded spots may be polished out
with crocus cloth. Never use emery cloth or sand­
paper. If scratches or corrosion are too deep to
be polished out, spider must be replaced.
Inspect plungers for scoring, scratches, or
corrosion. Light scratches may be polished out
with crocus cloth. If scratches or corrosion are
too deep to be polished out, plunger must be re­
placed.
. Inspect plunger seal for any cracking or
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deterioration. Any deterioration is unacceptable
and seal should be replaced.
ASSEMBLY OF WEDGE ASSEMBLY
(Refers to Figs. 33 and 34)
1. Install rollers in retaining cage.
2. Place washer in position on retaining cage.
3. Install wedge in retaining cage.
4. Position spring on wedge against washer
and com press enough to install return spring
washer and cotter pin.
INSTALLATION (Refer to Fig. 33)
1. Install new seals on anchor plungers as
shown in figure 35.
2. Install plungers and seals in housing as
shown in figure 36.
NOTE: Installation tool shown in figure 33 can
G M C S E R V I C E M A N U A L
5 Wedge Return Spring
Return Spring Washer
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7 Cotter Pin
Wedge
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PL U N G E R
PLU N G ER
Figure 3 5 — Installing Seal on Anchor Plunger
be made locally according to dimensions shown in
figure 37.
3. Insert plunger guide with new washer inside
slots in anchor plungers.
4. Install automatic adjuster components as
detailed in applicable procedure.
5. Install wedge assembly in actuation housing
(refer to fig. 38). Be sure rollers are seated cor­
rectly in retainer cage and make good contact with
plungers.
NOTE: Spring retainer washer has "ears" on
each side to be used as guides to assure correct
installation (see fig. 34). Housing has "slots" to
match "ears" on washer (see fig. 39).
. Install brake shoes as previously described
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