Chevrolet 1980 Light Duty Truck Service Manual page 362

5-8 BRAKES
C O N D IT IO N
D r a g g in g B ra k e s
(A v e ry lig h t d r a g is
p re s e n t in a l l disc
b r a k e s im m e d ia t e ly a f t e r
p e d a l is r e l e a s e d . ) — C o n tin u e d
G r a b b in g o r U n e v e n
B ra k in g A c tio n
P u ls a tio n (ro u g h n e s s )
F e lt d u r in g n o rm a l
b r a k e a p p lic a t io n .
PO S SIB LE C A U S E
3 . In c o rre c t p a r k in g b r a k e
a d ju s tm e n t on r e a r b ra k e s .
4 . C h e c k v a lv e in s ta lle d in
o u tle t to fr o n t disc
b ra k e s .
5 . In c o rre c t in s ta lla tio n o f in b o a r d
sh oe a n d lin in g .
1. A ll c o n d itio n s lis te d
u n d e r " P U L L S ".
2 . M a lfu n c tio n o f c o m b in a tio n
v a lv e .
3 . M a lfu n c tio n o f p o w e r
b r a k e u n it.
4 . B in d in g b r a k e p e d a l
m e c h a n is m .
1. U n e v e n p a d w e a r c a u s e d
b y c a lip e r n o t s lid in g
d u e to im p r o p e r c le a r ­
a n c e o r d ir t.
2 . U n e v e n ro to r w e a r
c a u s in g a thickness
v a r ia t io n b e tw e e n th e
tw o b r a k in g s u rfa c e s .
C O R R E C T IO N
3 . C h e c k a n d r e a d ju s t to
c o rre c t s p e c ific a tio n s .
4 . C h e c k m a s te r c y lin d e r o u tle t
a n d re m o v e c h eck v a lv e if
p re s e n t.
5 . R e fe r to c a lip e r in s ta lla tio n in
th is s e c tio n .
1. A ll c o rre c tio n s lis te d
u n d e r " P U L L S ".
2 . R e p la c e a n d b le e d system .
3 . C h e c k o p e r a tio n a n d
r e p a ir , if n e c e s s a ry .
4 . C h e c k a n d lu b r ic a t e , if
n e c e s s a ry . P ossibly r e p la c e
p e d a l b u s h in g a n d /o r
s p a c e r.
1. R em ove c a lip e r a n d c o rre c t
as n e ce s s a ry .
2 . M a c h in e roto rs as fo llo w s :
a . M a c h in e roto rs to o b ta in a
c ir c u m fe r e n tia l thickn ess v a r ia t io n no
g r e a t e r th a n . 0 0 0 5 " in 3 6 0 ° a n d a
la t e r a l ru n o u t no g r e a t e r th a n .0 0 4 "
(m a x . r a te o f c h a n g e n o t e x c e e d .0 0 1 "
in 3 0 ° ).
b . C h e c k c a lip e r fr e e n e s s . W it h ro to r
r e m o v e d , in s ta ll c a lip e r a n d m o u n tin g
b o lts (p in s ). C h e c k f o r
c le a r a n c e a t b o th to p a n d b o tto m o f
c a lip e r . If less th a n . 0 0 5 " is f o u n d , f i l e
w ith a f l a t f i l e u n til a t le a s t . 0 0 5 " is
o b t a i n e d . D O N O T EXC E E D A
M A X IM U M o f .0 1 2 " p e r e n d o r .0 2 4 "
to ta l c le a r a n c e . C a l i p e r c le a r a n c e to
in b o a r d a n d o u tb o a r d r e a c tio n p a d s
must b e e q u a l w ith in .0 0 4 " b o th a t th e
to p a n d b o tto m o f th e c a lip e r . This is to
e n s u re c o rre c t a lig n m e n t o f c a lip e r to
k n u c k le d u r in g a b r a k e a p p lic a t io n .
c. R em ove c a lip e r a f t e r fre e n e s s c h e c k .
C le a n p in s a n d s le eve s, r e p la c e " O "
rin g s , a n d a p p l y a lig h t c o a tin g o f
s ilic o n e g r e a s e o r e q u iv a le n t to a l l
c o n ta c t p o in ts a n d " O " rin g s .
. 0 0 5 " - . 0 1 2 "
LIGHT T R U C K S E R V IC E M ANUAL