REAR DISC BRAKE MOAN INSTALL DAMPER

Subject: REAR DISC BRAKE MOAN (INSTALL DAMPER)

Models Affected: 1989-91 FIREBIRD MODELS WITH J-65 (REAR DISC BRAKES)

Condition:

---------- Moan-type noise from vehicles with J-65 (rear disc brakes). This moan is most likely to occur during slow speed turns or when backing up.

Cause:

------ Stick slip of rear friction material on rotor during light braking sets up sympathetic vibration (moan) of rear suspension and body structure components.

Correction:

------------ To eliminate this moan noise, a damper has been added in production. A kit, P/N 10198312** is available from GMSPO which includes 2 dampers, 2 bolts and 2 nuts. Install the dampers as shown in the following Illustration.

1. Install the bolt and nut on the park brake cable bracket, and torque the nut to 45 N.m (33 lbs.ft.).

2. Attach the damper to the end of the bolt and torque to 45 N.m (33 lbs. ft.).

Also, the rear brake pads, P/N 10174840* should be replaced.

* Parts are currently available from GMSPO.

** Parts are expected to be available on June 3, 1991. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while the 400 control is in place.

Labor Operation Number: T1727 Labor Time : .8 Hours

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.