Chevrolet Light Duty Truck 1973 Service Manual page 317

Probable Cause
1 Excessive clearance between l i n i n g s and drum.
.
2. Automatic a d ju s te rs not working.
3. . Leaking conduits.
4. Leaking wheel c y l i n d e r .
5. Leaking master c y l i n d e r .
6. A i r in system.
7. Plugged master c y li n d e r f i l l e r cap.
8. Improper brake f l u i d .
9. Low f l u i d l e v e l .
Probable Cause
1 A i r trapped in h y d ra u lic system.
.
2. Improper brake f l u i d .
3. Improper l i n i n g thickness or lo c a t io n .
4. Drums worn too t h i n .
5. Master c y li n d e r f i l l e r vent clogged.
Probable Cause
1
Brake adjustment not c o r r e c t .
.
2. I n c o r r e c t l i n i n g .
3. Grease or f l u i d soaked l i n i n g .
4. Improper f l u i d .
5. Frozen master or wheel c y li n d e r p is to n s .
6. Brake pedal bindin g on s h a f t .
DIAGNOSIS—DRUM BRAKES
LOW PEDAL OR PEDAL GOES TO TOE BOARD
SPRINGY, SPONGY PEDAL
E X C E SSIV E PED A L PRESSU RE REQ U IR ED TO STOP V E H IC LE
Remedy
1 A djust brakes.
.
2. Make forward and reverse stops; i f pedal stays low,
r e p a i r f a u l t y a d ju s te r s .
3. Repair or repla ce f a u l t y p a rts .
4. Overhaul wheel c y l i n d e r , as o u t lin e d p re v io u s ly in
t h i s s e c tio n .
5. Overhaul master c y l i n d e r as o u t lin e d p re v io u s ly in
t h i s s e c tio n .
6. Bleed system.
7. Clean f i l l e r cap vent hole s; bleed system.
8. Flush system and r e f i l l w ith G M Hydraulic Brake F lu id
Supreme No. 11 (o r e q u i v a le n t ) .
9. F i l l r e s e r v o ir w ith G M Hydraulic Brake F lu id Supreme
No. 11 (o r e q u i v a le n t ) ; bleed system.
Remedy
1 Remove a i r by ble e din g.
.
2. Flush and bleed system using G M Hydra ulic Brake F lu id
Supreme No. 11 (o r e q u iv a le n t ) .
3. I n s t a l l new l i n i n g o r replace shoe and l i n i n g .
4. Replace drums.
5. Clean vent or repla ce cap; bleed brakes.
Remedy
l A djust the brakes.
.
2. I n s t a l l new l i n i n g s .
3. Repair grease seal or wheel c y l i n d e r .
1in in g s .
.
4
Flush out system; f i l l w ith G M Hydraulic Brake F lu id
Supreme No. 11 (o r e q u i v a le n t ) ; bleed system.
5. Overhaul master or wheel c y li n d e r s as o u t lin e d
p r e v io u s ly in t h i s s e c tio n .
6. L u b rica te w ith Delco Brake Lube #5450032 (or e q u iv a le n t).
BRAKES 5-51
I n s t a l l new
LIGHT DUTY TRUCK SERVICE MANUAL