Chevrolet 1977 light duty truck Service Manual page 388

C O N D IT IO N
B rake roughness o r c h a tte r
(P e d a l Pulsates) — C o n tin u e d
Excessive P e d a l E ffort
Excessive P e d a l Travel
D ra g g in g Brakes
(A very lig h t d ra g is
p resent in a ll disc
b rakes im m e d ia te ly a fte r
p e d a l is re le a s e d .)
POSSIBLE CAUSE
5. Shoe reversed (steel
a g a in s t iro n).
1. M a lfu n c tio n in g pow er
b ra ke.
2. P a rtia l system f a ilu r e .
3. Excessively worn shoe
a n d lin in g .
4. Piston in c a lip e r stuck
o r sluggish.
5. F a d in g b ra k e s d u e to
incorrect lin in g .
1. P a rtia l b ra k e system
f a ilu r e .
2. In s u ffic ie n t flu id in
m aster c y lin d e r.
3. A ir tra p p e d in system.
4 . R e a r b ra k e not a d ju s tin g .
5 . B ent shoe a n d lin in g .
1. M a s te r c y lin d e r pistons
not re tu rn in g
correctly.
2. Restricted b ra k e pipes
or hoses.
CO R R E C TIO N
5 . R eplace shoe a n d lin in g a n d
m achine ro tor w ith in
s p ecification s.
1. Check p ow er b ra k e a n d r e p a ir
if necessary.
2. C heck fro n t a n d re a r b ra k e
system a n d re p a ir, if
necessary. A lso, check
a n d re p a ir b ra k e w a rn in g
lig h t circuit if a f a ile d
system is fo u n d a n d lig h t
d id not fun ctio n.
3 . C heck a n d re p la c e in a x le
sets.
4 . Remove c a lip e r a n d re b u ild .
5 . Remove a n d re p la c e with
o rig in a l e q u ip m e n t lin in g
(or e q u iv a le n t).
1. C heck both fro n t a n d re a r
system fo r a fa ilu r e a n d
re p a ir. Also check a n d
r e p a ir w a rn in g lig h t circuit.
It should h ave in d ic a te d
a fa ilu r e .
2 . Fill reservoirs with
a p p ro v e d b ra k e flu id . Check
fo r leaks. Check w a rn in g
lig h t.
3 . B leed system.
4 . A djust re a r b rakes a n d
r e p a ir auto adjusters.
5 . R eplace a x le set o f shoe
a n d lin in g .
1. W ith reservoir cover o ff,
check fo r flu id spurt
a t bypass holes as p e d a l
is dep ressed. Adjust push
ro d , if necessary, or
re b u ild m aster c y lin d er.
2. C heck fo r soft hoses or
d a m a g e d pipes a n d re p la c e
w ith new hoses a n d new
d o u b le -w a lle d steel
b ra k e tu b in g .