ANTI-LOCK BRAKE PEDAL SQUEAK (INSTALL NEW SHIM)

SUBJECT: ANTI-LOCK BRAKE PEDAL SQUEAK

Some 1988-90 E and K cars may experience a condition of a squeak or scraping noise during application of the brake pedal. This may be caused because the brake pedal pushrod is not centered vertically in the spring cage, and the bottom surface of the pushrod (hex portion) contacts the inner diameter of the spring cage.

Repair:

------- 1. Remove the hush panel.

2. Inspect for a contact condition between the spring cage and the pushrod by pulling the rubber boot to the side, refer to Figure 1. (If contact is not present, refer to step 9 of this bulletin.)

3. Remove the central power supply.

4. Loosen the four mounting nuts from the pushrod bracket assembly, under dash.

5. Remove the cross-car brace, when applicable, underhood.

6. Have an assistant gently lift the ABS hydraulic booster while inserting ONE shim, P/N 3520709, between the front of dash noise barrier and the brake booster mounting bracket gasket. The shim is designed to be inserted onto both lower mounting studs of the hydraulic booster mounting adapter, refer to Figure 2.

7. Tighten nuts to 15 Ft.lbs./20 N-m.

8. Verify that interference condition is no longer present.

9. Apply lubricant to the area where the pushrod is attached to the brake pedal pivot pin. Refer to Figure 2.

10. Replace cross-car brace, central power supply, and hush panel.

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.