Inspection Procedure 2
DIAGNOSISSTEP 1. Check whether the brake fluid is low, is the correct fluid (ATF, engine oil, etc.) or is contaminated (debris, sand, etc.).
If faulty, refill or replace with the specified brake fluid DOT 3 or DOT 4. Bleed the brakes if necessary. Then go to Step 9.
If normal, go to Step 2.
STEP 2. Check for spongy (not firm brakes).
1. With engine not running, depress the brake pedal rapidly several times to deplete booster vacuum reserve.
2. With the brake pedal fully released, depress the brake pedal slowly until it stops.
3. With a measuring stick (ruler, etc.) next to the brake pedal, depress the pedal firmly and measure the distance the pedal traveled. If greater than 20 mm (0.8 inch), bleed the brakes to remove air in the fluid.
Then go to Step 9.
If normal, go to Step 3.
STEP 3. If equipped with rear drum brakes, check the lining and brake drum contact.
If not, go to Step 4.
Put chalk on the inner surface of the brake drum. Rub the lining against the drum inner surface.
NOTE: Clean off chalk after check.
If the lining wipes off, or at least smudges, the chalk across the full width of the lining, go to Step 4.
If not, replace the shoe and lining assemblies on both sides. Then go to Step 9.
STEP 4. Check the brake booster function.
If faulty, replace the part. Then go to Step 9.
If normal, go to Step 5.
STEP 5. Check the auto adjuster function.
If faulty, repair it. Then go to Step 9.
If normal, go to Step 6.
STEP 6. Check for pinched or restricted brake tube or hose.
If pinched or restricted, replace that complete section of brake tube or brake hose. Then go to Step 9.
If normal, go to Step 7.
STEP 7. Check for oil, water, etc., on the pad or lining contact surfaces of all brakes.
If found, replace the part and determine source/cause of foreign material. Recheck symptom. If the symptom is eliminated, diagnosis is complete. If the symptom is not eliminated, start over at step 1. If a new symptom surfaces, refer to the symptom chart.
If condition no longer exists, diagnosis is complete. If condition persists, go to Step 8.
If normal, go to Step 8.
STEP 8. Check the proportioning valve operation.
If faulty, replace the part. Then go to Step 9.
STEP 9. Recheck symptom.
If the symptom is eliminated, diagnosis is complete. If the symptom is not eliminated, start over at step 1. If a new symptom surfaces, refer to the symptom chart.