Chevrolet Light Duty Truck 1973 Service Manual page 312

5 -4 6 BRAKES
12. Place guide plate on anchor pin.
13. Install pull back springs.
14. Remove the "knock out" plug (if necessary) and
install a new metal plug in the brake drum
adjusting hole.
15. Install the brake drum.
16. Install the propeller shaft.
REAR BRAKES RPO H-22 (Fig. 79)
Brake shoe adjustment takes place when brakes are
applied with a firm pedal effort while the vehicle is
backing up. Applying the brakes moves actuators which
turn the star wheels and rotate the adjusting screws
outward from the anchor brackets. This action adjusts
the shoe until clearance between the lining and drum is
within proper limits.
Should low pedal heights be encountered, it is
recommended that numerous forward and reverse stops
be performed with a firm pedal effort until a satisfactory
pedal height results.
Retracting Self Adjusters
Access holes are located in the flange plate. These holes
are for service purposes in the event retracting of the
brake shoes is required to remove the drum. In order to
back off the adjuster, insert a screwdriver, index a corner
of the screwdriver blade with the hole in the actuating
lever and hold the lever away from the star wheel. Using
a brake adjusting tool, back off the star wheel.
Brake Drums, Shoes and Linings
Removal
1. Raise the vehicle on a hoist.
2. Retract self adjusters if necessary and remove
brake drums.
A N C H O R
SUPPORT x
FRICTIO N
SPRING
HO LD D O W N
PIN
Fig. 79 -Rear Brake-Used with RPO H-22
A C T U A T IN G LEVER
C A M
A C T U A T IN G
LEVER LINK
OVER RIDE
' LEVER
OVER RIDE
SPRING
RETURN
SPRING
A C T U A T IN G
STAR LE
v e r
W HEEL
3. Using Tool J-22348, remove the brake shoe pull
back springs (fig. 80).
4. Loosen the actuating lever cam cap screw and while
holding the star wheel end of the actuating lever
past the star wheel, remove the cap screw and cam.
5. Remove the brake shoe hold down springs and pins
by compressing the spring with Tool J-22348 and, at
the same time, pushing the pin back through the
flange plate toward the tool. Then, keeping the
spring compressed, remove the lock from the pin
with a magnet (fig. 81).
. Lift off the brake shoe and self adjuster as an
6
assembly.
7. The self adjuster can now be removed from the
brake shoe by removing the hold down spring and
pin.
NOTE: The actuating lever, override lever
and spring are an assembly. It is recom­
mended that they not be disassembled for
service purposes unless they are broken. It is
much easier to assemble and disassemble the
brakes leaving them intact.
. Thread the adjusting screw out of the anchor
8
support and remove and discard the friction spring.
9. Clean all dirt out of brake drum. Inspect drums for
roughness, scoring or out-of-round. Replace or
recondition drums as necessary.
NOTE: See Section on "BRAKE DRUMS".
10. Carefully pull lower edges of wheel cylinder boots
Fig. 8 0 -Removing Pull Pack Spring with Tool
J-22348
LIGHT DUTY TRUCK SERVICE MANUAL