LIGHT BRAKE DRAG-may BE BRAKE SWITCH ADJUSTMENT

Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS

THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED.

Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system.

This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied.

If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check:

Passenger Cars Only:

The following steps should be used to check brake switch adjustment:

1. Remove the driver-side hush panel (refer to Figure 1).

2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment.

3. Replace the hush panel.

4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly.

If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes.

For warranty purposes use:

Labor Operation Number: N2440

Labor Time: .3 hour

TRUCK ONLY:

Service Procedure:

1. Depress the brake pedal and press the switch in until it is firmly seated in the clip.

Audible "clicks' can be heard as the threaded portion of the switch is pushed through the clip.

2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard.

For stop lamp switch adjustments on vehicies repaired under warranty use:

Labor Operation Number: T7945

Labor Time: .2 Hr.

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.