Inspection Procedure 7: Squealing Noise When Brakes Are Not Applied
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 a 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 a 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 spring for damage.
Q: Is there a 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 the pads. 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 the calipers. Then go to Step 10.
NO: Go to Step 7.
STEP 7. Check the wheel bearings for end play.
(1) Remove the brake discs.
(2) Place a dial gauge as shown, and measure the end play while moving the hub in the axial direction.
Limit: 0.05 mm (0.002 inch)
Q: Does the measured end play exceed the limit?
YES: Replace the faulty hub assembly. Then go to Step 10.
NO: Go to Step 8.
STEP 8. Check whether the brake booster or master cylinder return is insufficient.
Q: Is the brake booster or master cylinder return insufficient?
YES: Replace the part. Then go to Step 10.
NO: Go to Step 9.
STEP 9. Adjust the brake pedal or brake booster pushrod. Testing and Inspection Installation Service Points
Q: Are the brake pedal and the brake booster pushrod adjusted correctly?
YES: Go to Step 10.
NO: Adjust the brake pedal or the brake booster pushrod. Then go to Step 10.
STEP 10. Recheck symptom.
Q: Is the symptom eliminated?
YES: The procedure is complete.
NO: Start over at step 1. If a new symptom surfaces, refer to the symptom chart. Symptom Chart