Chevrolet Light Duty Truck 1973 Service Manual page 318

5 -5 2 BRAKES
EXCESSIVE PEDAL PRESSURE REQUIRED TO STOP VEHICLE (CONT.)
Probable Cause
7. Glazed 1in in g s.
8. Bellmouthed, barrel-shaped or scored drums.
Probable Cause
1. Brake adjustment not c o r r e c t.
2. Loose fla n ge p la te on f r o n t axle .
3. A small amount o f grease or f l u i d on l i n i n g s .
4. Charred l i n i n g s .
5. In c o r r e c t 1 in i r i g .
6. Wheel bearings loose.
7. Linin g loose on shoe.
8. Excessive dust and d i r t in drums.
9. Bellmouthed, barrel-shaped or scored drums.
Probable Cause
1. Master c y li n d e r compensating p o rt plugged.
2. Swollen cup in master c y li n d e r .
3. Master c y li n d e r p isto n not re tu r n in g .
4. Weak shoe r e t r a c t i n g s pring s.
5. Wheel c y li n d e r pistons s t i c k i n g .
Probable Cause
1. Drums o u t-o f-ro u n d .
2. Loose brake drum on hub.
3. Worn or loose wheel bearings.
4. Bent rear axle .
DIAGNOSIS—DRUM BRAKES
7. Sand surface o f l i n i n g s .
8. Replace or resu rfa ce drums in l e f t and r i g h t hand p a ir s .
LIGHT PEDAL PRESSURE-BRAKES TOO SEVERE
1. A djust the brakes.
2. Tighten p la te s .
3. Replace the l i n i n g s .
4. Replace the 1in in g s .
5. I n s t a l l new l i n i n g s .
6. Adjust wheel bearings.
7. Replace l i n i n g o r shoe and l i n i n g .
8. Clean and sand drums and l i n i n g s .
9. Turn drums in p a irs or repla ce.
BRAKE PEDAL TRAVEL DECREASING
1. Open, use a i r or .015 w ir e .
2. Replace rubber p a r ts .
3. Overhaul master c y li n d e r as o u t lin e d p re v io u s ly in
4. Replace spring s.
5. Overhaul wheel c y li n d e r as o u t lin e d p r e v io u s ly in
PULSATING BRAKE PEDAL
1. Re finis h drums.
2. Tighten.
3. Replace or a d ju s t.
4. Replace axle.
Remedy
Remedy
Remedy
Flush system.
Hydraulic Brake F lu id Supreme No. 11 (or e q u iv a le n t ) .
t h i s s e c tio n .
t h is s e c tio n .
Remedy
Remove any b u rr in bore.
R e f i l l w ith G M
LIGHT DUTY TRUCK SERVICE MANUAL