INSPECTION/MAINTENANCE PROCEDURE FOR RESTRICTED

SUBJECT: INFORMATION - INSPECTION/MAINTENANCE PROCEDURE FOR RESTRICTED MOVEMENT BETWEEN BRAKE PAD AND CALIPER AND/OR KNUCKLE

MODELS: 1990.5 BUICK ELECTRA 1991 - 1996 BUICK PARK AVENUE 1991 - 1997 BUICK LESABRE, SKYLARK 1990 - 1992 CADILLAC FLEETWOOD 1990 - 1996 CADILLAC DEVILLE 1992 CADILLAC SIXTY SPECIAL 1992 - 1996 CADILLAC ELDORADO, SEVILLE 1994 - 1996 CADILLAC CONCOURS 1992 - 1996 CHEVROLET BERETTA, CAVALIER, CORSICA, LUMINA APV 1993.5 - 1997 CHEVROLET CAMARO 1997 CHEVROLET MALIBU 1990.5 - 1996 OLDSMOBILE NINETY EIGHT 1991 OLDSMOBILE CALAIS 1991 - 1997 OLDSMOBILE EIGHTY EIGHT 1992 OLDSMOBILE TORONADO 1992 - 1996 OLDSMOBILE SILHOUETTE 1992 - 1997 OLDSMOBILE ACHIEVA 1997 OLDSMOBILE CUTLASS 1992 - 1994 PONTIAC SUNBIRD 1991 - 1997 PONTIAC BONNEVILLE, GRAND AM 1992 - 1996 PONTIAC TRANS SPORT 1993.5 - 1997 PONTIAC FIREBIRD 1995 - 1996 PONTIAC SUNFIRE

CUSTOMER SERVICE NOTES: YOUR CUSTOMERS SHOULD BE MADE AWARE OF THE MAINTENANCE REQUIREMENTS OF THEIR VEHICLE. THESE OWNER RESPONSIBILITIES ARE DESCRIBED AND LISTED IN THE OWNER'S MANUAL UNDER PERIODIC MAINTENANCE INSPECTIONS. (EXAMPLE: BRAKE LININGS, TIRE AND WHEEL INSPECTION AND ROTATION ARE OWNER MAINTENANCE.)

SOME OF THE ABOVE LISTED VEHICLES MAY EXHIBIT RESTRICTED MOVEMENT BETWEEN THE BRAKE PAD AND THE CALIPER AND/OR KNUCKLE.

MOVEMENT MAY BE RESTRICTED BY:

A. DEBRIS BUILD-UP, OR B. CORROSION

IF THE PADS DO NOT HAVE FREE MOVEMENT WITHIN THE CALIPER AND/OR KNUCKLE, ONE OR BOTH PAD(S) MAY REMAIN AGAINST THE ROTOR. THIS MAY LEAD TO THE FOLLOWING:

A. EARLY PAD WEAR-OUT B. ROTOR THICKNESS VARIATION (MAY RESULT IN PULSATION) C. ROTOR DAMAGE IF NOT CORRECTED IN TIME.

THE FOLLOWING PROCEDURE SHOULD BE USED TO INSPECT FOR AND CORRECT RESTRICTED PAD MOVEMENT:

INSPECTION -

1. MOVE WHEEL AND TIRE FROM VEHICLE.

2. MOVE THE PISTON INTO THE CALIPER BORE USING A C-CLAMP (KENT- MOORE TOOL #J-42588 OR EQUIVALENT). REFER TO FIGURE 1.

NOTICE:

USE CARE TO AVOID PERMANENTLY BENDING THE ANTI-RATTLE CLIPS ON THE OUTBOARD BRAKE PAD, 5MM (1/8 INCH) IS SUFFICIENT.

3. CHECK THE OUTER BRAKE PAD FOR FREEDOM OF MOVEMENT RELATIVE TO THE KNUCKLE ABUTMENT. REFER TO FIGURE 2.

IMPORTANT:

THE BRAKE PADS MUST MOVE EASILY WITHIN THE KNUCKLE.

4. USING HANDS, PUSH THE CALIPER IN AS FAR AS POSSIBLE. THE LINING SHOULD RETRACT WITH THE PISTON/CALIPER HOUSING. REFER TO FIGURE 3.

5. CHECK THE INNER BRAKE PAD FOR FREEDOM OF MOVEMENT RELATIVE TO THE KNUCKLE ABUTMENT. REFER TO FIGURE 3.

6. REPEAT THIS PROCEDURE FOR THE OTHER SIDE OF THE VEHICLE.

7. IF ALL PADS MOVE FREELY, GO TO STEP #7 UNDER "CORRECTION" AND INSTALL THE WHEELS AND TIRES. IF MOVEMENT IS RESTRICTED, PROCEED WITH STEP #1 UNDER "CORRECTION".

CORRECTION -

IF RESTRICTED PAD MOVEMENT IS NOTED ON ONE OR MORE CALIPERS, PERFORM THE FOLLOWING "CLEAN AND LUBRICATE" PROCEDURE.

1. REMOVE THE BRAKE PADS FROM THE CALIPER.

2. REMOVE ALL DEBRIS AND CORROSION FROM THE KNUCKLE USING A WIRE BRUSH AT ANY POINTS WHERE THE BRAKE PADS COME IN CONTACT WITH THE KNUCKLE AND/OR CALIPER. IF THE CORROSION IS SEVERE, USE A SCRAPER FIRST. REFER TO FIGURE 4.

3. USING A WIRE BRUSH/SCRAPER, REMOVE ALL DEBRIS AND CORROSION FROM THE BRAKE PAD METAL BACKING SHOE IN THE AREAS WHERE THE SHOES CONTACT THE KNUCKLE AND/OR THE CALIPER. REFER TO FIGURES 2 AND 3.

4. COAT ALL AREAS OF THE KNUCKLE AND/OR CALIPER WHERE THE BRAKE PAD SHOES CONTACT USING A HIGH TEMPERATURE SILICONE GREASE, P/N 18010909 OR EQUIVALENT. REFER TO FIGURE 4.

5. INSTALL THE BRAKE PADS AND CALIPER ON THE VEHICLE.

6. REPEAT STEPS 1 - 5 ON THE OTHER CALIPER BRAKE ASSEMBLY. IF ONE CALIPER NEEDS SERVICE, DO BOTH SIDES.

7. REINSTALL WHEELS AND TIRES ON THE VEHICLE.

IMPORTANT:

EVENLY TORQUE WHEEL NUTS TO SPECIFICATION USING A TORQUE WRENCH OR A TORQUE LIMITING SOCKET/STICK.

A TORQUE WRENCH OR TORQUE STICK MUST BE USED TO INSURE THAT WHEEL NUTS ARE TIGHTENED TO SPECIFICATION. THIS SHOULD BE DONE IN THREE STEPS USING THE STAR PATTERN. FIRST, SNUG THE NUTS DOWN BY HAND. SECOND, USING THE STAR PATTERN AND A TORQUE STICK/WRENCH, TIGHTEN THE WHEEL NUTS TO ABOUT HALF THE FINAL TORQUE. THIRD, TIGHTEN THE WHEEL NUTS TO SPECIFICATION USING THE STAR PATTERN AND A TORQUE STICK/WRENCH. USE THE SAME AMOUNT OF IMPACT WRENCH OPERATING TIME AS WOULD NORMALLY BE USED WITHOUT A TORQUE STICK.

8. PUMP THE BRAKE PEDAL AS MANY TIMES AS REQUIRED TO OBTAIN A FIRM BRAKE PEDAL.

CAUTION:

DO NOT MOVE THE VEHICLE UNTIL A FIRM BRAKE PEDAL IS OBTAINED. FAILURE TO OBTAIN A FIRM BRAKE PEDAL BEFORE MOVING VEHICLE MAY RESULT IN PERSONAL INJURY.

FIGURES: 4 ATTACHMENTS: 00

FIGURE 1: 1. KNUCKLE 2. CALIPER 3. ANTI-RATTLE CLIP 4. ROTOR

FIGURE 2: 5. KNUCKLE ABUTMENT 6. OUTER BRAKE PAD 8. GAP

FIGURE 3: 2. CALIPER 5. KNUCKLE ABUTMENT 7. INNER BRAKE PAD 8. GAP

FIGURE 4: A. CONTACT AREA 1. KNUCKLE

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.

COPYRIGHT 1996 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.