Inspection Procedure 7
INSPECTION PROCEDURE 7: Squealing Noise When Brakes Are Not AppliedDIAGNOSIS
STEP 1: Check whether the backing plate is bent or loose and interfering with the drum.
Q: Is there fault?
YES: Replace the part. Then go to Step 10.
NO: Go to Step 2.
STEP 2: Check whether the drum is damaged due to interference with the backing plate or shoe.
Q: Is there damage?
YES: Replace the part. Then go to Step 10.
NO: Go to Step 3.
STEP 3: Check the brake drum for wear and the shoe-to shoe spring for damage.
Q: Is there wear or damage?
YES: Replace the part. Then go to Step 10.
NO: Go to Step 4.
STEP 4: Check the brake discs for rust.
Q: Are the brake discs rusted?
YES: Remove the rust by using sand paper. If still rusted, turn the rotors with an on-the-car brake lathe. Then go to Step 10.
NO: Go to Step 5.
STEP 5: Check the brake pads for correct installation.
Q: Are the pads installed incorrectly?
YES: Repair it. Then go to Step 10.
NO: Go to Step 6.
STEP 6: Check the calipers for correct installation.
Q: Are the calipers installed incorrectly?
YES: Repair it. Then go to Step 10.
NO: Go to Step 7.
STEP 7: Check the wheel bearings for deterioration or damage, and the quality and quantity.
Q: Are the wheel bearings damaged or out of grease?
YES: Apply grease or replace the part. Then go to Step 10
NO: Go to Step 8.
STEP 8: Check whether the brake booster, master cylinder or wheel cylinder return is insufficient.
Q: Is the brake booster, master cylinder or wheel cylinder return insufficient?
YES: Replace the part. Then go to Step 10
NO: Go to Step 9.
STEP 9: Check that the brake pedal and brake booster pushrod are adjusted properly.
Q: Are the brake pedal and brake booster adjusted properly?
YES: Go to Step 10
NO: Adjust them. Then go to Step 10.
STEP 10: Recheck symptom.
Q: Is the symptom eliminated?
YES: Diagnosis is complete
NO: Start over at Step 1. If a new symptom surfaces, refer to the symptom chart. Symptom Chart For Inspection Procedues