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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 . . . . . . . . . . . . . . . . . . . . . . . . . 43 POWER BRAKE BOOSTER . . . . . . . . . . . . . . . . . . . . . . . . . 44 . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 . . . . . . . . . . . . . . . . . . . . . . . . . 45 ROTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 . . . . . . . . . . . . . . . . . . . . . . . . . 47 DRUM DIAGNOSIS AND TESTING - BRAKE DRUM STANDARD PROCEDURE - BRAKE DRUM . . . . . . . . . . . . . . . . . . . . . . . . . . 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 . . . . . . . . . . . . . . . . . . . . . . . . . . 48 WHEEL CYLINDERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 . . . . . . . . . . . . . . . . . . . . . . . . . 51 SUPPORT PLATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 . . . . . . . . . . . . . . . . . . . . . . . . . 53 CABLES ADJUSTMENTS - PARK BRAKE CABLE . . . . . . . . . . . . . . . . . . . . . . . . . 61 PEDAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 . . . . . . . . . . . . . . . . . . . . . . . . . 64 CABLE TENSIONER ADJUSTMENTS - PARK BRAKE CABLE . . . . . . . . . . . . . . . . . . . . . . . . . 65 BRAKES - BASE DIAGNOSIS AND TESTING BASE BRAKE SYSTEM Base brake components consist of the brake pads, calipers, brake drum & brake shoe assembly in the rear, rotors Brake diagnosis involves determining if the problem is related to a mechanical, hydraulic, or vacuum operated com- The first diagnosis step is the preliminary check. PRELIMINARY BRAKE CHECK 1. Check condition of tires and wheels. Damaged wheels and worn, damaged, or underinflated tires can cause pull, shudder, vibration, and a condition similar to grab. 2. If complaint was based on noise when braking, check suspension components. Jounce front and rear of vehicle and listen for noise that might be caused by loose, worn or damaged suspension or steering components. 3. Inspect brake fluid level and condition. Note that the brake reservoir fluid level will decrease in proportion to normal lining wear. Also note that brake fluid tends to darken over time. This is normal and should not be a. If fluid level is abnormally low, look for evidence of leaks at calipers, wheel cylinders, brake lines, and master cylinder. b. If fluid appears contaminated, drain out a sample to examine. System will have to be flushed if fluid is sep- arated into layers, or contains a substance other than brake fluid. The system seals and cups will also have 4. Check parking brake operation. Verify free movement and full release of cables and pedal. Also note if vehicle was being operated with parking brake partially applied. 5. Check brake pedal operation. Verify that pedal does not bind and has adequate free play. If pedal lacks free play, check pedal and power booster for being loose or for bind condition. Do not road test until condition is corrected. 6. Check booster vacuum check valve and hose. 7. If components checked appear OK, road test the vehicle. ROAD TESTING 1. If complaint involved low brake pedal, pump pedal and note if it comes back up to normal height. 5 - 2 BRAKES - BASE ND |