POWER BRAKE BOOSTER CHECK VALVE RATTLE-NEW KIT

VEHICLES AFFECTED: 1986 'A' Series With 2.5L (LR8) Engine

The power brake vacuum supply system on the 1986 'A' series equipped with a 2.5L (LR8) engine uses larger vacuum hoses and fittings than previous model years. This feature allows quicker vacuum booster response. Production cars that have been evaluated may exhibit a rattling noise caused by the fluttering of the vacuum booster check valve. This noise is apparent after the brake pedal has been released while the engine is running.

This condition can be confirmed by placing your hand on the check valve (located on the vacuum booster) while someone pumps the brake pedal. As the check valve flutters, a vibration will be felt. Production after September 13, 1985 will use a revised check valve to eliminate this condition. The service check valve kit, part number 18012017 will contain a revised valve. The check valve in the kit should be used to correct the above condition.

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.