Chevrolet 70 1969 Series, Shop Manual

Page: 269 / 913

BRAKES 5C-76
6. Lower rear wheels. Remove jack and wheel
blocks.
B R A K E D R U M R E M O V A L
1. Jack up at least one rear wheel. Block
wheels and release parking brake.
2. Disconnect universal joint at brake drum,
as instructed under applicable heading in "P R O ­
P E L L E R S H A F T S " (SEC. 4D).
3. Remove eight nuts and lock washers hold­
ing yoke flange and brake drum. Remove yoke
flange. Lift drum carefully off mounting bolts to
avoid damage to threads.
B R AKE D R U M IN S T A L L A T IO N
1. Lift brake drum and install carefully over
brake shoes and onto eight mounting bolts'. Install
yoke flange and eight nuts and lock washers. Tight­
en nuts alternately and evenly.
2. Adjust brake as directed under "Parking
Brake Adjustment."
3. Connect propeller shaft universal joint as
directed in "P R O P E L L E R S H A F T S ” (SEC. 4D )0
BR A K E S H O E R E M O V A L (Fig. 3)
N O T E : Output shaft flange is removed in fig­
ure 3 for clarity of illustration; it is not necessary
to remove flange to remove brake shoes.
1. Remove two return springs and anchor pin
link from cam ends of brake shoes. Spread ends
of brake shoes far enough to permit removal from
support plate. Remove shoes, then separate by
removing adjusting screw and adjusting screw
spring.
2. Replace lining if worn down close to rivet
heads. Rivet new lining securely and evenly on
shoes.
3. Inspect two shoe return springs, and adjust­
ing screw spring. Parts damaged or worn should
be replaced with new parts.
B R A K E S H O E IN S T A L L A T IO N (Fig. 3)
1. Apply thin coat of S-17 special lubricant
on surface of support plate at points in contact
with brake shoes. Apply S-17 sparingly to socket
end of adjusting screw and install adjusting screw
socket.
2. Insert adjusting screw between adjusting
ends of brake shoes. Adjusting wheel should be
nearest left shoe. Install adjusting screw spring.
3. Spread apart cam ends of brake shoes. Lift
shoes vertically and push into position on support
plate. Install anchor pin brace and two shoe re­
turn springs.
SUPPORT P L A T E R E M O V A L (Fig. 3)
1. Remove propeller shaft flange at mainshaft
as directed in "T R A N S M IS S IO N " (SEC. 7B) of this
manual.
2. Remove brake shoe and lining assemblies.
3. Remove cotter pin and clevis pin attaching
control lever to link.
4. Mark control lever and camshaft so that
parts may be properly reassembled. Loosen clamp
bolt and slide control lever off serrated camshaft.
Remove camshaft from camshaft bracket.
5. Remove bolts attaching plate to transmis­
sion rear bearing cap, then remove plate.
6. Remove cotter pin, nut, washer, and relay
lever. Inspect relay lever bushing. Replace dam ­
aged or badly worn bushings.
SUPPORT P L A T E IN S T A L L A T IO N (Fig. 3)
1. Position support plate on pilot of transmis­
sion rear bearing cap or retainer and align bolt
holes. Insert four bolts and tighten securely.
2. Install camshaft in camshaft bracket. Align
control lever mark with mark on camshaft and in­
stall control lever. Tighten clamp nut.
3. Install brake shoe and lining assemblies.
4. Install propeller shaft flange at mainshaft
as directed in "T R A N SM ISS IO N " (SEC. 7B).
5. Replace relay lever, washer, and nut on
shaft. Tighten nut lightly, then back up to first hole
and install new cotter pin. Nut should not be tight
enough to restrict movement of relay lever. Insert
clevis pin through holes in control lever and link
and secure with new cotter pin.
Figure 3— Internal Expanding Type Brake Installed
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK 5HOP MANUAL
ioy -
1 Return Springs
2 Anchor Pin Link
3 Camshaft
4 Control Lever
5 Link
6 Relay Lever
7 Brake Shoe
8 Plate Bolt
9 Adjusting Screw
Spring
10 Adjusting Screw
11 Support Plate
_____ TPM-8399