IMPROVED BRAKE PEDAL FEEL NEW BRAKE BOOSTER RELEASED

SUBJECT: IMPROVED BRAKE PEDAL FEEL (NEW BRAKE BOOSTER)

VEHICLES AFFECTED: 1990-91 K1 TRUCKS W/JB3 BRAKES

Some customers may comment about hard brake pedal feel or reduced assist on some 1990-91 "K1" truck series equipped with JB3 brakes. A new larger displacement brake vacuum booster will be installed in "K1" series production effective with VIN numbers listed below. The new booster is being installed to improve power assist during braking and to improve the "feel" of the brakes, especially for customers who operate their vehicle heavily loaded most of the time.

Customers with vehicles built with the old booster who operate vehicles heavily loaded may prefer the improved brake pedal feel of the new booster. If so, the new brake booster can be installed on vehicles with this condition. When installing the new booster, follow the procedure in Light Duty C/K Service Manuals X-9031 and X-9131, Section 5A.

VEHICLES INVOLVED

The smaller displacement booster can be identified by the letters BM printed on a white tag on the booster. The new larger displacement booster has the letters HR printed on the tag.

VIN BREAKPOINT

Fort Wayne GMC 1GTDC14HXMZ519105 Chevrolet 1GCDK14Z3MZ168422

Oshawa Not Involved

Pontiac East GMC 1GTGK24K1ME518837 Chevrolet 1GCEK14CXME159028

SERVICE PARTS INFORMATION

Part Description

18012114 Brake Booster

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.