Chevrolet 10 Series 1970 Service Manual page 270

BRAKES 5-32
assem bles on the upper groo ve o f the spring reta in er
pin fro m the wheel cy lin d er side.
6. Adjust brakes - - In itial manual lining adjustment.
a. Back o ff starw heel adjustments.
b. Center each shoe:
Insert p ry tool against backing plate curl and shoe
and slid e shoe up o r down in anchor slots until
leading and tra ilin g edges o f the lining are equal
distance fro m the inner curl o f the brake backing
plate.
c. Set adjuster hex e c c en tric on each shoe web. R o­
tate hex e c c en tric until linkage aligns starw heel
crank pawl with cen ter line o f adjuster screw . A
1/16 inch wide m ille d slot located on the anchor
support is the aligning m ark.
cen trics with th eir self-tap p in g screw s and install
drum.
d. A t each shoe starw h eel, rem ove adjustment slot
co v e r fro m exposed side o f backing plate. Insert
adjusting T o o l J-4707 and rotate starw heel until
lining drags on
handle toward axle while using inner side of the
adjuster slo t as fulcrum fo r the tool, rotating the
starw h eel teeth away fro m the axle.
o ff starw h eel while rotating drum forw ard , until
drag just is re lie v e d .
ning clearan ce by backing o ff 8-10 m ore notches
and rep lace slot c o v e r. Autom atic adjustm enters
w ill now m a i n t a i n
clearan ce.
BRAKE SHOE LININGS
Bonded Lining
Brake linings on front and re a r brakes on S eries 10
a re attached to brake shoes by a special bonding p r o ­
ce ss . When lining becom es
replacem ent is n ecessa ry,
factory-bonded shoe and lining assem b lies be used fo r
replacem ent.
Riveted Lining
Brake linings on S e ries 20 through 60 are riveted to the
brake shoes and may be replaced. Only brake linings
sp ecified in the P a rts Books, o r equivalent, should be
used. These linings may be purchased in replacem ent
sets o f four linings and su fficien t riv e ts o f c o r r e c t s p e c i­
fication s. When rep lacin g linings, make sure that shoes
a re clean and that linings are installed in a manner that
w ill prevent gaps between lining and shoe.
Conventional lining replacem en t equipment should be
used. Make sure lining fits fir m ly against shoe, and that
r iv e ts are p ro p e rly upset.
WHEEL CYLINDERS
NOTE: A lw ays use denatured alcohol o r brake
fluid to clean any main cylin d er o r wheel c y lin ­
d er parts o r when flushing a brake system .
C AUTIO N: N E V E R
C L E A N IN G S O LV E N T SUCH AS GASOLINE, K E -
ROSENE, C A R B O N -T E T R A C H L O R ID E ,
TONE, P A IN T TH IN N E R OR UNITS OF LIK E
N A TU R E AS THESE SO LVENTS D E T E R IO R A T E
Take care not to m ar lining.
Lock adjusted e c ­
drum. To tighten, m ove tool
Then back
P ro vid e additional run­
norm al f a c i n g to drum
worn to the extent that
it is recom m ended
USE M I N E R A L - B A S E
A C E -
RUBBER P A R T S , CAUSING TH EM TO BECOME
SO FT AND S W O L L E N
SHORT TIM E .
Removal (Fig.57)
Duo-Servo Type
1. Jack up axle and rem ove wheel, brake drum and
brake shoes
"
Rem oval.
2. At front, disconnect m etal brake tube fro m flex ib le
hose at fra m e, disconnect hose fro m fra m e, then un­
screw hose fitting fro m wheel cylin d er connector, o r
fro m wheel cylin d er housing where connector is not
used. A t re a r, disconnect m etal brake tube fro m
wheel cylin der connector.
3. Rem ove cap screw s and w ashers attaching wheel
cylin d er to flange plate and rem ove cylin der assem ­
bly. Rem ove
housing.
Tw inplex Type
1. Jack up axle and rem ove brake shoes as directed
under Brake Shoe Rem oval.
2. Disconnect
connector at
brake tube connecting wheel cylin ders at outer side
o f flange plate.
o f each cylinder.
3. Rem ove cap screw s and lock w ashers attaching wheel
cylin ders to flange plate, then rem ove wheel c y lin ­
d ers and heat shield. Rem ove brake line connectors
fro m cylin der housings.
Type " F" (Fig. 58)
1. Jack up axle and rem ove brake shoes as directed
under " Brake Shoe R em o va l."
2. Disconnect axle brake tube fro m inlet connector at
upper cylin der.
that
connecting tube fitting to upper cylin d er and rem ove
bolt attaching connecting tube fittin g to lo w er c y lin ­
d er. Rem ove connecting tube and fittings assem bly.
3. Rem ove one la rg e and two sm a ll cap screw s attach­
ing each cylin d er to flange plate, then rem ove c y lin ­
d ers from backing plate.
Type " FR-3"
1. Jack up axle and rem ove brake shoes as d irected
under " Brake Shoe R em o va l."
2. Rem ove bolts
wheel cylin d ers at inner side o f flange plate.
3. Rem ove two cap screw s and lock w ashers attaching
each wheel cylin d er to flange plate.
cylin d ers and heat shields, then rem ove heat shields
fro m cylinders.
Disassembly
Type " F" (Fig. 58 )
Pu ll boot o ff end o f cylinder, then rem ove boot and
piston. Pu ll boot o ff piston. Brake shoe guide is p ressed
into piston and cannot be rem oved.
cup fille r , and spring fro m
va lve fro m cylinder.
All Types Except Type " F" (Figs. 5 7 and 5 9 )
P u ll boots o ff ends of cylin ders and rem ove push rods
fro m boots. Push pistons, cups and spring out of c y l­
inder. Duo-Servo and Tw inplex type wheel cylin d ers are
IN AN E X T R E M E L Y
as directed under
connector, i f used, fro m
brake tube fro m re a r wheel cylin d er
inner side o f flange plate.
Rem ove dust shield fro m upper end
Rem ove inlet connector attaching
attaching brake line connectors to
Rem ove wheel
Rem ove piston cup,
cylin der. Rem ove b leeder
CHEVROLET TRUCK SERVICE MANUAL
" Brake Shoe
cylin der
Rem ove