FRONT BRAKE CLICK DURING SLOW SPEED APPLICATION

FRONT BRAKE 'CLICK' DURING SLOW SPEED BRAKE APPLICATION VEHICLES AFFECTED: 1981 'A' MODEL VEHICLE SERIES THE FOLLOWING SUPERSEDES INFORMATION REGARDING CLICK ON BRAKE APPLY COVERED IN P.S.B. #101 GROUP 50 DATE APRIL 30, 1981. FRONT BRAKE CLICK DURING SLOW SPEED BRAKE APPLICATION IN SUBJECT MODELS HAS BEEN CAUSED BY LACK OF CLEARANCE BETWEEN DISC CALIPER AND STEERING KNUCKLE TOP OUTBOARD STOP. THIS HAS ALLOWED THE CALIPER TO SNAP ON THE TOP INBOARD STOP INSTEAD OF BEING ALLOWED TO MAKE AN EVEN CONTACT ON BOTH OF THESE SURFACES. THIS CONDITION CAN BE CORRECTED BY PERFORMING THE FOLLOWING ON BOTH LEFT AND RIGHT SIDE FRONT BRAKE CALIPERS: 1.USE FEELER GAUGE AND CHECK CLEARANCE BETWEEN CALIPER AND TOP OUTBOARD STOP. REFER TO ILLUSTRATION. 2.IF NO CLEARANCE EXISTS BETWEEN THE CALIPER AND THE LARGE (OUTBOARD) FORWARD KNUCKLE STOP, REMOVE THE CALIPER ASSEMBLY AND FILE KNUCKLE TO OBTAIN APPROXIMATELY .005 INCH (.127MM) CLEARANCE WITH THE CALIPER. CARE SHOULD BE TAKEN NOT TO EXCEED .010 INCH (.254 MM) CLEARANCE AND TO KEEP SURFACE PARALLEL TO THE SMALL ABUTMENT SURFACE. 3.CLEAN REMAINING KNUCKLE AND CALIPER TOP AND BOTTOM STOP SURFACES WITH FINE EMERY CLOTH. 4.REASSEMBLE CALIPER ASSEMBLY PER INSTRUCTIONS IN 1981 CHASSIS SERVICE MANUAL.

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.