Chevrolet 30 Series 1967 Service Manual page 238

BRAKES 5-22
Fig. 41—A lign in g Drum Tang with W h ee l Hub
A lternate M ethod of Adjustment
a. Using the brake drum as an adjustment fixture,
turn the star wheel until the drum slides over the
brake shoes with a slight drag.
b. Turn the star wheel 1-1/4 turns to retract the
shoes. This will allow sufficient lining to drum
clearance so final adjustment may be made as
described in Step 4.
3. Install the drum and wheel.
NOTE: 1: If lanced area in brake drum was
knocked out, be sure all metal has been removed
from brake compartment. Install new hole cover
in drum to prevent contamination of the brakes.
ANCHOR
SUPPORT
FRICTION
SPRING
HOLD DOWN
PIN
Fig . 42 —Tw inplex S e lf Adjusting Rear Brake (40 and 50 Series)
ACTUATING LEVER
ADJUSTING CAM
ACTUATING
LEVER LINK
OVER RIDE
LEVER
RIDE
SPRING
SPRING
ACTUATING
STAR LE
ver
WHEEL
Fig. 43—Removing Pull Back Springs Using Tool J-22348
NOTE: 2: Make certain when installing drums
that drums are installed in the same position as
when removed with the drum locating tang in
line with the locating hole in the wheel hub
(fig. 41).
4. Make final adjustment by driving and stopping ve­
hicle until satisfactory brake pedal height is obtained
as described under
earlier in this section.
REAR BRAKES (40 AND 50 Series)
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 out­
ward from the anchor brackets (fig. 42). This action
adjusts the shoe until clearance between the lining and
drum is within proper limits.
Should low pedal heights be encountered, it is recom­
mended that numerous forward and reverse stops be
performed with a firm pedal effort until a satisfactory
pedal height results.
Retracting Self Adjusters (Rear)
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, remove the cover from the
access hole and insert a screw driver. Index a corner of
the screw driver 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 and place on jack stands.
2. Retract self adjusters and remove brake drums.
"S e lf Adjusting Features"
CHEVROLET TRUCK SERVICE M ANUAL