PROPORTIONER VALVE SQUEAK DURING HEAVY, FAST BRAKING

1984-1985 6000 STE 1986 6000 STE WITHOUT ANTILOCK BRAKE SYSTEM (JM4)

Some vehicles may exhibit a short, squeaking noise during heavy, fast, brake apply. This noise only occurs while the brake pedal is being depressed and stops immediately when the brake pedal stops. The squeak comes from the proportioner valves attached to the master cylinder. The squeak does not affect brake performance. Vehicles found objectionable, can be corrected by installing new front and rear proportioner valves.**

Old Part Numbers 18010934 (Front) Code FY 18010936 (Rear) Code RY

New Part Numbers 18014134 (Front) Code FR 18014135 (Rear) Code RR

* * Front refers to the proportioner valve closest to the front of the vehicle, and rear is the one closest to the dash.

Use applicable labor time and operation number.

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.