For 1990-2009 cars

# DISC BRAKE SQUEAL DURING APPLICATION - DIAGNOSIS

#### VEHICLES AFFECTED: All Models

Disc brake systems offer many performance advantages, including improved resistance to brake fade and improved performance when brakes are wet. A high pitched squeak or squeal is sometimes experienced when these brakes are applied with light to moderate pressure. This squeak can be a source of annoyance and customer dissatisfaction, however, this squeak should be considered normal when all other components of the braking system are functioning correctly.

If the brake system is functioning correctly and it is the judgment of the Dealership's Service Department that the demonstrated condition is normal brake noise, the customer should be assured that this is an operating characteristic of disc brakes and no repair attempted. Efforts to completely eliminate these noises are frequently temporary.

Other noises should not be arbitrarily considered normal. They should be diagnosed as outlined in the Service Manual. An example of a similar noise requiring corrective action is the constant high pitched squeal that is emitted by the disc brake pad wear warning sensor, observed when the vehicle is in motion (except when braking).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.