Chevrolet 10 Series 1970 Service Manual page 262

BRAKES 5-24
backing up. Applying the b rakes m oves actuators which
turn the star wheels and rotate the adjusting s c rew s out­
ward fro m the anchor brack ets.
shoe until clearan ce between the lining and drum is with­
in p rop er lim its.
Should low pedal heights be encountered, it is r e c o m ­
mended that numerous fo rw a rd and re v e r s e
p erfo rm e d with a fir m pedal e ffo rt until a sa tisfa cto ry
pedal height resu lts.
Retracting Self Adjusters (Rear)
A c c es s holes are located in the flange plate.
holes a re fo r s e rv ic e purposes in the event retra ctin g of
the brake shoes is requ ired to rem ove the drum. In o rd e r
to back o ff the adjuster,
a ccess hole and in sert a sc re w d riv e r. Index a c o rn er o f
the s c re w d r iv e r blade with the hole in the actuating le v e r
and hold the le v e r away fro m the star wheel. Using a
brake adjusting tool, back o ff the star wheel.
Brake Drums, Shoes and Linings
Removal
1. R aise the veh icle and place on jack stands.
2. R etract s e lf adjusters and rem ove brake drums.
NOTE: If brake drums are worn s e v e r e ly , it
may be n ecessa ry
scre w s as p revio u sly outlined.
3. Using T ool J-22348 rem o ve the brake shoe pull back
springs (fig . 45).
NOTE: Since wheel c ylin d e r piston stops are
incorporated in the anchor brackets, it is not
n ecessary to in stall wheel cylin d er clam ps when
the brake shoes a re
brake pedal must not be depressed while the
drums are rem oved.
4. Loosen the actuating le v e r cam cap s c re w and while
holding the star wheel end o f the actuating le v e r past
the star wheel, rem ove
5. Rem ove the brake shoe hold down springs and pins
by com p ressin g the spring with T o o l J-22348 and, at
the sam e tim e, pushing the pin back through the
flange plate toward the tool. Then, keeping the spring
com pressed, rem ove
magnet (fig . 46).
6. L ift o ff the brake
assem bly.
7. The s e lf adjuster can now be rem oved fro m the brake
shoe by rem ovin g the hold down spring and pin.
NOTE: The actuating le v e r , o v e rrid e le v e r and
spring are an assem b ly.
that they be disassem b led fo r s e rv ic e purposes
unless they are broken. It is much e a s ie r to a s ­
sem ble and d isassem b le the brakes leavin g them
intact.
8. Thread the adjusting s c re w out of the anchor support
and rem ove and d iscard the fric tio n spring.
9. Clean a ll d irt out o f brake drum. Inspect drums fo r
roughness, scorin g o r out o f round. Replace o r r e ­
condition drums as n ecessary.
NOTE: See Section on " B RAKE DRUMS" .
10. C a refu lly pull lo w e r edges o f wheel cylin d er boots
away fro m cylin d ers.
This action adjusts the
stops be
These
rem ove the c o v e r fro m the
to re tra ct the adjusting
rem oved. H ow ever, the
the cap sc rew and cam.
the lock fro m the pin with a
shoe and s e lf adjuster as an
It is recom m ended
If brake fluid flow s out, o v e r ­
haul of the wheel cylinders is n ecessa ry.
NOTE: A slight amount of fluid is n ea rly a l­
ways presen t and acts as a lubricant fo r the
piston.
11. Inspect flange plate fo r o il leakage past axle shaft
o il seals. Install seals if n ecessary.
12. Check a ll flange plate attaching bolts to make sure
they a re tight (150 lb. ft. torque). Clean a ll d irt and
rust fro m shoe contact fa c es on flange plate using
em ery cloth.
13. Thoroughly clean adjusting sc rew s and threads in
the anchor brackets.
Installation
1. Put a light film o f Bendix o r D elco brake lube o r
Lubriplate o r equivalent on shoe bearing su rfaces o f
brake flange plate and on threads o f adjusting screw .
2. Thread adjusting screw
b racket without fric tio n spring to be sure threads
a re clean and screw turns ea sily.
screw , position a new fric tio n spring on sc rew and
rein sta ll in anchor bracket.
3. A ssem b le s e lf adjuster assem bly to brake shoe and
position actuating le v e r
4. P osition hold down pins in flange plate.
5. Install brake shoe and s e lf adjuster a ssem b lies onto
hold down pins, indexing ends o f shoes with wheel
cylin d er push rods
NOTE: Make sure the toe o f the shoe is against
the adjusting s crew (fig. 47).
6. Install cup, spring and reta in er on end of hold down
pin. Using T ool J-22348 com press the spring. With
spring com pressed, push the hold down pin back
through the flange plate toward the tool and install
the lock on the pin.
7. Using T ool J-22348
springs.
F ig . 4 7 —Brake Shoe and S e lf A d ju s te r Assembly
com pletely into anchor
Then rem ove
link on o v e rrid e le v e r .
and legs o f fric tio n springs.
in sta ll brake shoe return
CHEVROLET TRUCK SERVICE MANUAL