BRAKE LINING CONTAMINATION
Brake lining contamination is mostly a product of leaking calipers or worn seals, driving through deep water puddles,
or lining that has become covered with grease and grit during repair. Contaminated lining should be replaced to
avoid further brake problems.
WHEEL AND TIRE PROBLEMS
Some conditions attributed to brake components may actually be caused by a wheel or tire problem.
A damaged wheel can cause shudder, vibration and pull. A worn or damaged tire can also cause pull.
Severely worn tires with very little tread left can produce a grab-like condition as the tire loses and recovers traction.
Flat-spotted tires can cause vibration and generate shudder during brake operation. A tire with internal damage such
as a severe bruise, cut, or ply separation can cause pull and vibration.
BRAKE NOISES
Some brake noise is common with rear drum brakes and on some disc brakes during the first few stops after a
vehicle has been parked overnight or stored. This is primarily due to the formation of trace corrosion (light rust) on
metal surfaces. This light corrosion is typically cleared from the metal surfaces after a few brake applications caus-
ing the noise to subside.
BRAKE SQUEAK/SQUEAL
Brake squeak or squeal may be due to linings that are wet or contaminated with brake fluid, grease, or oil. Glazed
linings and rotors with hard spots can also contribute to squeak. Dirt and foreign material embedded in the brake
lining will also cause squeak/squeal.
A very loud squeak or squeal is frequently a sign of severely worn brake lining. If the lining has worn through to the
brake pads in spots, metal-to-metal contact occurs. If the condition is allowed to continue, rotors can become so
scored that replacement is necessary.
BRAKE CHATTER
Brake chatter is usually caused by loose or worn components, or glazed/burnt lining. Rotors with hard spots can
also contribute to chatter. Additional causes of chatter are out-of-tolerance rotors, brake lining not securely attached
to the shoes, loose wheel bearings and contaminated brake lining.
THUMP/CLUNK NOISE
Thumping or clunk noises during braking are frequently not caused by brake components. In many cases, such
noises are caused by loose or damaged steering, suspension, or engine components. However, calipers that bind
on the slide surfaces can generate a thump or clunk noise.
5 - 204
BRAKES - BASE - SERVICE INFORMATION
DR/DH