SERVICE MANUAL UPDATE-SEC. 5 (PARKING BRAKE NON-ADJUSTABLE)

Subject: SERVICE MANUAL UPDATE - SECTION 5 BRAKES (PARKING BRAKE IS NON-ADJUSTABLE) Models Affected: 1992 GRAND AM MODELS

This bulletin serves to update the Parking Brake adjustment procedure in the 1992 Grand Am service manuals SECTION 5, Pages 13-15.

The following is the updated information concerning its operation. Please update your 1992 Service Manuals SECTION 5 accordingly by making reference to the 1993 Service Manual SECTION 5F.

Parking brake adjustment is not necessary. This is a self adjusting system and damage may result from attempting to adjust or modify this system in any way. It may be necessary to adjust the rear brakes to obtain the proper tension in the system, refer to SECTION 5C.

The effort required to fully apply this system is lower than that on previous foot operated systems. Heavy foot pressure can cause the lever to "bottom out" (reach its full downward travel position). This does not indicate that the cable tension is low. The system has been designed to meet or exceed all F.M.V.S.S. and General Motors requirements. The required cable tension is generated prior to the "bottom out" condition. The ability to "bottom out" the lever under heavy foot pressure does not necessarily indicate a system deficiency.

DIAGNOSIS

The park brake system can be checked for its ability to generate sufficient cable tension by performing the following steps:

1. Check the drum brake clearance and reset if required. Refer to SECTION 5C.

2. Fully apply and release the foot park brake lever 4 times.

3. Apply lever to the 2 click position.

4. Raise the car and suitably support. Refer to SECTION OA.

5. Check park brake cable tension by attempting to turn right rear wheel with both hands. Wheel should only rotate backward, NOT forward.

6. Release park brake and check for rear brake drag. Rear wheels should turn freely (some light shoe to drum contact may be heard).

7. If excessive drag is felt, remove drum (refer to SECTION 5C) and check for the Parking Brake hanging up or binding.

8. If sufficient tension is not obtained refer to SECTION 5C for adjustment.

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.