BRAKES-AIR
TRUCK SERVICE MANUAL
8. Remove cam roller assemblies from brake shoes.
9. Remove clevis pin, connecting brake chamber push
rod to slack adjuster. Remove lock ring, cotter key
or capscrew holding the slack adjuster to end of the
camshaft. Remove slack adjuster.
10. Push or tap the camshaft out of the spider or backing
plate bracket. Be sure to keep spacer washers in
proper order for correct reassembly.
11. Inspect camshaft bushings and replace if necessary.
CLEANING AND INSPECTION
Fig. 2 Exploded View of Front Brake Group
Clean all brake parts in cleaning fluid and wipe
Legend for Fig. 2
them dry. It is particularly important that brake shoes
1
WASHER, adjuster spacing
with lining removed be cleaned thoroughly. Use steam,
2
BUSHING, camshaft bracket
solvent or wire brush to remove all traces of rust and
3
BRACKET, w/BUSHING, camshaft
4
CAMSHAFT
corrosion. If any rust or corrosion is allowed to remain
5
WASHER, camshaft spacing
on the lining surface or shoe table of the shoes, it is
6
BRACKET, brake chamber
possible that the lining may crack while being attached to
7
PLATE, w/BRACKET, backing
the shoe.
8
PIN, shoe anchor (4)
9
RETAINER, anchor pin
Brake drums should be thoroughly cleaned. See "Brake
10
LINING, brake
Drums".
11
SHOE, w/LINING
12
SPRING, shoe return
REASSEMBLY
13
RETAINER, brake shoe roller
14
ROLLER, brake shoe
15
LUBRICATOR, 1/8 straight
After the various components of the brake
16
ADJUSTER, slack, assy
assemblies have been serviced, the brakes may be
17
CHAMBER, brake, assy
reassembled by reversing the disassembly procedure.
18
PIN, brake chamber yoke
PIN, cotter
It is recommended that newly installed brake
19
YOKE, brake chamber
lining be circle ground before installing the brake drums.
20
PIN, brake shoe guide
Circle grinding the lining to fit drum assures full contact
WASHER, guide pin outer
WASHER, bowed
between lining and drum.
WASHER, guide pin inner
WASHER, "C"
The brake lining may either be circle ground
either when lining is installed on shoes (See "Brake
1. Position the truck on floor stands and remove wheel
Lining and Shoes") or after shoes are installed on
and drum.
vehicle.
2. Remove dust shields from rear axle brake groups.
3. Remove the shoe return spring or springs.
The brake shoe grinder which mounts on the
4. Remove "C" washers from shoe guide pins (if so
spindle is used after installing shoes with new lining (Fig.
equipped).
5). The grinder rotates about on its axis, the grinding
5. Remove anchor pin retainers, washers, felt retainers
head equalizes the distance between the two brake shoe
and felts from anchors.
lining surfaces and the drum surface. Grind the new
6. Remove brake shoes. To remove brake shoes from
lining approximately .070" less than the inside diameter
rear brake groups, the anchors must be removed.
of brake drum. Make certain that the brake is fully
To do so, remove anchor pin retainers, felt retainers,
released before grinding.
felts, lock wire and lock screws or pins (Figs. 3 and
4).
7. The brake shoe anchors can now be re moved from
the front axle brake group by removing nut and
lockwasher from anchor then forcing the anchor from
the backing plate.
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