Chevrolet 70 1969 Series, Shop Manual

Page: 209 / 913

BRAKES 5A-16
B R A K E SH O E R E M O V A L (Fig. 14)
1. Jack up axle and remove hub and brake
drum assembly as directed in "F R O N T HUBS A N D
BE A R IN G S" (SEC. 3D).
2. Remove both brake shoe return springs,
using brake spring pliers.
3. Remove C-washer and flat washer from
each adjusting cam and hold-down stud. Lift shoes
off backing plate.
C L E A N IN G A N D INSPECTION
1. Clean all dirt out of brake drum. Inspect
drum for roughness, scoring, or out-of-round.
Replace or recondition brake drum as necessary.
Refer to "Brake D ru m s" later in this section.
2. Inspect wheel bearings and oil seals as di­
rected in "F R O N T HUBS A N D BE AR IN G S" (SEC. 3D).
3. Check backing plate attaching bolts to make
sure they are tight. Clean all dirt off backing plate.
4. Inspect brake shoe return springs. If broken,
cracked, or weakened, replace with new springs.
5. Check cam and shoe guide stud and fric­
tion spring on backing plate for corrosion or bind­
ing. C am stud should turn easily with an 8 " wrench,
but should not be loose. If frozen, lubricate with
kerosene or penetrating oil and work free.
6 . Examine brake shoe linings for wear. Lin­
ings should be replaced if worn down close to rivet
heads. Refer to "Brake Shoe Relining" in this
section.
BR AKE S H O E IN S T A L L A T IO N
1. Install anti-rattle spring washer on each
cam and shoe guide stud, pronged side facing ad­
justing cam.
2. Place shoe assembly on backing plate with
cam and shoe guide stud inserted through hole in
shoe web; locate toe in wheel cylinder piston shoe
guide and position heel in slot in anchor block.
3. Install flat washer and C-washer on cam
and shoe guide stud. Crimp ends of C-washer.
4. After installing both shoes, install brake
shoe return spring. To install each spring, place
spring end with short hook in toe of shoe, then
using brake spring pliers, stretch spring and se­
cure long hook end in heel of opposite shoe.
1 Wheel Cylinder
6 Brake Shoe Adjusting
2 Brake Shoe Return Cam
Spring
7 Brake Shoe Guide
3 Backing Plate Washer
4 Brake Shoe 8 Brake Shoe Guide
5 Brake Lining
C-Washer
/i 5 ^
9 Adjusting Cam and
4
/
A
10
Shoe Guide Stud
Shoe Guide Anti-
11
Rattle Washer
Adjusting Cam Spring
i ° n
y/
1
2
Figure 14— Type “F” Front Brake Assembly
5. Install hub and brake drum as directed in
" F R O N T HUBS A N D B E A R IN G S" (SEC. 3D).
6 . Adjust brake as previously directed under
"Brake Adjustments."
TYPE “FR-3” REAR BRAKE
(Refer to Figure 15)
Each brake is equipped with two double-end
wheel cylinders which apply hydraulic pressure
to both the toe and the heel of two identical, self-
centering shoes. The shoes anchor at either toe
or heel, depending upon the direction of drum ro­
tation. Brake anchor supports and backing plate
are bolted to the axle housing flange. The supports
have removable slotted anchor pins at the shoe
heels, and adjusting screws at the shoe toes. A d­
justing screws act as anchors in the reverse di­
rection of rotation. Each adjusting screw is thread­
ed into or out of its support by means of an adjust-
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L