Chevrolet 70 1969 Series, Shop Manual

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BRAKES 5A-21
A L L BRAKES D R A G W H E N A D J U S T M E N T IS K N O W N T O BE C O R R E C T
PROBABLE C A U SE
R E M E D Y
1. Pedal does not return to stop.
1. Lubricate the pedal.
2. Improper fluid.
2. Replace rubber parts and fill with recom­
mended brake fluid.
3. Compressing or bypass port of master
3. Open by air or .015 wire. Remove any burr
cylinder closed.
in bore.
4. Use of inferior rubber parts.
4. Install proper parts.
O N E W H E E L D R A G S
PROBABLE C A U SE
R E M E D Y
1
.
Weak or broken shoe retracting springs.
1
.
Replace the defective brake shoe springs and
lubricate the brake shoe ledges.
2 . Brake shoe to drum clearance too small or the
brake shoe eccentric is not adjusted properly.
2. Adjust.
3. Loose wheel bearings.
3. Adjust wheel bearings.
4. Wheel cylinder piston cups swollen and dis­
torted or the piston stuck.
4. Rebuild cylinders.
5. Pistons sticking in wheel cylinder.
5. Clean or replace pistons; clean cylinder bore.
6 . Drum out-of-round.
6 . Grind or turn both front or rear drums.
7. Obstruction in line.
7. Clean out or replace.
8 , Distorted shoe.
8. Replace.
9. Defective lining.
9. Replace with specified lining.
R E A R BRAKES D R A G
PROBABLE C A U SE
R E M E D Y
1. Maladjustment.
1. Adjust brake shoes.
P U L L S T O O N E SIDE
PR OB ABLE C A U SE
R E M E D Y
1. Grease or fluid soaked lining.
2. Loose wheel bearings, loose backing plate on
rear axle or front axle or loose spring bolts.
3. Linings not of specified kind.
4. Tires not properly inflated or unequal wear of
tread. Different tread non-skid design.
5. Linings charred.
6 . Water, mud, etc., in brakes. ■
1. Replace with new linings.
2. Adjust the wheel bearing, tighten the backing
plate on the rear and front axles and tighten
spring bolts.
3. Install specified linings.
4. Inflate the tires to recommended pressures.
Rearrange the tires so that a pair of non-skid
tread surfaces of similar design and equal
wear will be installed on the front wheels, and
another pair with like tread will be installed
on the rear wheels.
5. Sand the surfaces of the lining.
6 . Remove any foreign material from all of the
brake parts and inside of the drums. Lubricate
the shoe ledges.
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK SH O P M A N U A L