Document 156GrGeLQMbOgdZMNDx8Lym0a

BRAKE SYSTEM DIAGNOSIS AND TESTING LESSON ONE-MODULE 1 Abnormal Noise Noises that do indicate a need for service: Continuous grinding noise that indicates worn out pads. Continuous squeal noise. - Remember, some occasional brake squeal may be normal. Pad Clack. Moan. Brake Noise Diagnosis To determine the cause of brake noise, perform the following tests: Determine whether the noise is coming from inside or from outside the vehicle. - A clicking or squeaking noise that comes from under the dash may be caused by: A faulty pedal bushing. A misaligned push rod. A misaligned or improperly installed switch. - A hissing noise that comes from under the dash may be caused by: A leaking vacuum brake booster. A leaking automatic parking brake release switch or servo assembly. Inspect each wheel brake assembly for worn, damaged or improperly installed components including: - Shoes and pads. - Anti-rattle springs and clips. - Caliper slide mechanisms. - Return springs. - Hold down springs. - Parking brake mechanisms. Brake System Diagnosis and Repair September, 2005 21