Chevrolet 70 1969 Series, Shop Manual

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TROUBLESHOOTING CHART
BRAKES 5A-19
L O W P E D A L O R P E D A L G O E S T O T O E BO A RD
PROBABLE C A U SE R E M E D Y
1. Excessive clearance between linings and drum.
1. Adjust brakes.
2. W eak brake hose. 2. Replace with new hose.
3. Leaking conduits.
3. Repair or replace faulty parts.
4. Leaking wheel cylinder.
4. Clean and rebuild.
5. Leaking master cylinder.
5. Clean and rebuild.
6 . Leaking master cylinder check valve. 6 . Install new check valve.
7. Air in system. 7. Bleed system.
8 . Plugged master cylinder filler cap.
8 . Clean filler cap vent holes; bleed system.
9. Improper brake fluid.
9. Flush system and refill with recommended
brake fluid.
10. Low fluid level
10. Fill reservoir with brake fluid; bleed system.
SPRINGY, SPO N G Y P E D A L
R E M E D Y
PR OB ABLE C A U S E
1. Air trapped in hydraulic system.
1. Remove air by bleeding.
2. Improper brake fluid.
2. Flush, refill and bleed system. Use recom­
mended brake fluid.
3. Improper lining thickness or location.
3. Install specified lining or replace shoe and
lining.
4. Drum s worn too thin.
4. Replace drums.
5. Master cylinder filler vent clogged.
5. Clean vent or replace cap; bleed brakes.
6 . Weak hose.
6 . Install new hose.
E X C E S S IV E P E D A L PR ESSU RE R E Q U IR E D T O STOP
PROBABLE C A U S E R E M E D Y
1. Brake adjustment not correct.
1. Adjust the brakes.
2. Incorrect lining.
2. Install specified linings.
3. Grease or fluid soaked lining.
3. Repair grease seal or wheel cylinder. Install
new linings.
4. Lining not in full contact.
4. Grind lining to proper radius.
5. Improper fluid.
5. Flush out system; fill with recommended fluid;
bleed.
6 . Frozen master or wheel cylinder pistons.
6 . Recondition or replace all cylinders.
7. Brake pedal binding on shaft.
7. Lubricate.
8. Glazed linings.
8 . Sand surface of linings.
9. Bellmouthed, barrel-shaped or scored drums.
9, Replace or resurface drums in R .H . and L .H .
p a irs.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L