GMC 4000 Series Service Manual page 244

AUTOMATIC ADJUSTER
All Stopmaster brakes have automatic adjust­
er mechanisms. The basic part of the adjuster
(refer to fig. 28) is a plunger assembly which is
made up of the adjusting plunger, the actuator, and
the adjusting bolt. The actuator is threaded in­
ternally to receive adjusting bolt. On the external
iurface, there are buttress type teeth. The plunger
guide is free to slide in a drilled hole in the spider
housing and has teeth to match those on the exter­
ior surface of the actuator. A spring, gasket, and
bolt are used to hold the guide in contact with the
actuator.
Figure 29 is an illustration of an automatic
1 Brake Air Chamber Assembly
2 Non-Pressure Half
3 Brake Shoe Assembly
4 Adjusting Bolt Assembly
5 Identification Ring
6 Spanner Nut Retainer
7 Spanner Nut
8 Plunger Seal and Retainer
9
Adjusting Pawl (Plunger Guide)
10
Hollow Cap Screw
G M C S E R V I C E M A N U A L
1 Adjusting Bolt and Shoe
2 Actuator
3 Plunger Seal
4 Adjusting Plunger
5 Plunger Guide
11 Gasket
12 Spring
13 Adjusting Sleeve (Actuator)
14 Adjusting Plunger
15 Wedge Spring Retainer
16 Roller
17 Plunger Housing
18 Anchor Plunger (Solid)
19 Guide Screw
20 Gasket
Figure 2 9 — Autom atic Adjuster A ssem b led
2
Retainer Assembly
6 Plunger Guide Spring
7 Plunger Guide Washer
8 Plunger Guide Bolt
Figure 2 8 — Automatic Adjuster Components
21 Plunger Seal and Retainer
22 Roller Retaining Cage
23 Wedge Spring
24 Cotter Key
25 Washer
26 Wedge Shaft
27 Wedge Guide
28 Diaphragm Plate (Push Rod)
29 Rubber Boot
30 Pressure Half
Sec. 5B
Page 237
AIR BRAKES
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