RATTLE/BUZZ FROM I/P DURING BRAKE APPLY AND RELEASE

* VEHICLES AFFECTED: 1987-90 'J/N', 1987-90 'A'

This bulletin has been revised to include all 1987-90 'A, J, and 'N' models, and correct the part number.

On some 1987-90 'J', 'N', and 'A' models, customers may comment on a rattle or buzz type noise that seems to come from the instrument panel area in front of the driver. The noise is most likely to occur during brake apply or release, during low speed or parking lot maneuvers.

To repair this condition, install a new brake booster check valve, P/N #18012017.

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.