GMC 4000 Series Service Manual page 210

PULLS TO ONE SIDE (Cont'd.)
PROBABLE CAUSE
10. Brake dragging.
11. Weak ch assis springs, loose U-bolts, loose
steering gear, etc.
12. Loose steering.
13. Unequal camber.
14. Clogged or crimped hydraulic line.
15. Wheel cylinder size different on opposite sides.
16. Loose king pin.
17. Bad drum.
ONE WHEEL LOCKS
PROBABLE CAUSE
1. Gummy lining.
2. Tire tread slick.
WET WEATHER: BRAKES GRAB OR WONT T HOLD
PROBABLE CAUSE
1. Linings too sensitive to water.
2. Dirty brakes.
3. Bent backing plate - - opening.
4. Scored drums.
BRAKES SQUEAK
PROBABLE CAUSE
.
1
Backing plate bent or shoes twisted.
2. Metallic particles or dust imbedded in lining.
3. Lining rivets loose or lining not held tightly
against the shoe at the ends.
4. Drums not square or distorted.
5. Incorrect lining.
6. Shoes scraping on backing plate ledges.
7. Weak or broken hold down springs.
8. Loose wheel bearings.
9. Loose backing plate, anchor, drum, wheel
cylinder.
10. Linings located wrong on shoes.
G M C S E R V I C E M A N U A L
10. Check for loose lining. Adjust.
11. Replace spring, tighten U-bolts, adjust
steering gear, etc.
12. Repair and adjust.
13. Adjust to "Specifications."
14. Repair or replace line.
15. Replace with correct cylinders.
16. Replace king pins or bushings.
17. Refinish drums in pairs.
1. Reline.
2. Match up tire treads from side to side.
1. Reline.
2. Clean out.
3. Straighten.
4. Grind or turn in pairs.
.
1
Straighten or replace damaged parts.
2. Sand the surfaces of the linings and drums. Re­
move all particles of metal that may be found
in the surfaces of the linings.
3. Replace rivets and/or tighten lining by re­
riveting.
4. Turn or grind or replace drums.
5. Replace lining.
6. Apply brake lube to ledges. Replace with new
shoe and linings, if distorted.
7. Replace defective parts.
8. Tighten to proper setting.
9. Tighten.
10. Install linings correctly.
Sec. 5A
Page 203
HYDRAULIC BRAKES
REMEDY
REMEDY
REMEDY
REMEDY