Inspection Procedure 7

INSPECTION PROCEDURE 7: Squealing Noise when Brakes are not Applied

DIAGNOSIS

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 any 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 any 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.

Refer to Testing and Inspection or Service and Repair.

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.