JB3 Brakes - Hard Brake Pedal

91chevy11

GMC NUMBER: 91-5-67

GROUP: 5 Brakes

DATE: March, 1991

CORPORATE
NUMBER: 065026R


SUBJECT:
IMPROVED BRAKE PEDAL FEEL

MODELS:
1990-91 K1 TRUCKS


Some customers may comment of hard brake pedal or lack of assist on some 1990-91 K1 trucks equipped with JB3 brakes. During the 1991 model year, a new larger displacement brake vacuum booster will be installed in production on the above trucks. 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 boosters 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 Technicians can identify the old smaller displacement booster by a white tag on the booster. The letters BM will be printed in the tag. The new service booster has the letters HR printed in the tag.


VIN BREAKPOINTS

Fort Wayne GMC 1GTDC14HXMZ519105
Chevrolet 1GCDK14Z3MZ168422
Oshawa Not Involved
Pontiac East GMC 1GTGK24K1ME518837
Chevrolet 1GCEK14CXME159028


SERVICE PARTS INFORMATION

Part Number Description
18012114 Brake Booster

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use:

Labor Operation: H1220

Labor Time: 1.0 hr.