CAMPAIGN: REAR BRAKE WHEEL CYLINDER ROTATION

CONDITION GENERAL MOTORS HAS DETERMINED THAT A DEFECT WHICH RELATES TO MOTOR VEHICLE SAFETY EXISTS IN SOME 1978 AND 1980 BUICK CENTURYS AND REGALS. IT IS POSSIBLE THAT A REAR BRAKE WHEEL CYLINDER COULD ROTATE DUE TO ENLARGEMENT OF THE WHEEL CYLINDER PILOT HOLE IN THE BACKING PLATE. IF SUCH ROTATION BECOMES EXCESSIVE, CONTACT COULD BE LOST BETWEEN THE WHEEL CYLINDER PISTON AND THE BRAKE SHOE AND COULD RESULT IN THE LOSS OF REAR BRAKE FLUID AND CONSEQUENTLY THE LOSS OF REAR BRAKING ACTION. THESE VEHICLES ARE EQUIPPED WITH A DUAL BRAKING SYSTEM. IN THE EVENT OF A REAR SYSTEM LOSS, THE FRONT BRAKE SYSTEM WOULD REMAIN FUNCTIONAL AND THE BRAKE WARNING LIGHT ON THE INSTRUMENT PANEL WOULD BE LIT. ABSENCE OF REAR BRAKING AT A TIME WHEN MINIMUM STOPPING DISTANCE IS REQUIRED COULD RESULT IN A VEHICLE CRASH WITHOUT PRIOR WARNING. DEALER ACTION TO PREVENT THE POSSIBILITY OF THIS CONDITION OCCURRING ON VEHICLES INVOLVED, DEALERS ARE TO INSTALL A RETAINING BRACKET ON BOTH REAR WHEEL CYLINDERS TO PREVENT THEM FROM ROTATING. THESE PARTS ARE AVAILABLE IN A PARTS KIT FROM GMWDD. NORMAL MAINTENANCE ITEMS SUCH AS WORN BRAKE LININGS, LEAKING WHEEL CYLINDERS, AND PARKING BRAKE CABLES FOUND DURING THE CAMPAIGN THAT REQUIRE REPLACEMENT WILL BE AT THE CUSTOMER'S EXPENSE. CUSTOMER MUST BE CONTACTED AND THEIR CONSENT OBTAINED PRIOR TO REPLACEMENT OF ANY MAINTENANCE PARTS. DEALERS ARE TO SERVICE ALL VEHICLES SUBJECT TO THIS CAMPAIGN AT NO CHARGE TO THE OWNER, REGARDLESS OF MILEAGE, AGE OF VEHICLE, OR OWNERSHIP, FROM THIS TIME FORWARD. WHENEVER A VEHICLE SUBJECT TO THIS CAMPAIGN IS TAKEN INTO YOUR USED VEHICLE INVENTORY OR IS IN YOUR DEALERSHIP FOR SERVICE IN THE FUTURE, YOU SHOULD TAKE THE STEPS NECESSARY TO BE SURE THE CAMPAIGN CORRECTION HAS BEEN MADE BEFORE RESELLING OR RELEASING THE VEHICLE. VEHICLES INVOLVED ALL 1978 1980 BUICK CENTURYS AND REGALS ASSEMBLED AT THE PLANTS LISTED BELOW: MODEL YEAR ASSEMBLY PLANT PLANT VIN CODE 1978 FRAMINGHAM G 1980 FLINT H DEALER MATERIAL IF YOUR DEALERSHIP HAS VEHICLES INVOLVED IN THIS CAMPAIGN, YOU WILL RECEIVE THE FOLLOWING ITEMS: - LIST OF ALL VEHICLES INVOLVED IN THIS CAMPAIGN IN THE AREA OF YOUR DEALERSHIP. - ONE CAMPAIGN IDENTIFICATION LABEL FOR EACH VEHICLE. INVOLVED VEHICLES HAVE BEEN IDENTIFIED BY VEHICLE IDENTIFICATION NUMBER COMPUTER LISTINGS. COMPUTER LISTINGS CONTAIN THE COMPLETE VEHICLE IDENTIFICATION NUMBER, OWNER NAME AND ADDRESS DATA, AND ARE FURNISHED TO THE INVOLVED DEALERS WITH THE CAMPAIGN BULLETIN. OWNER NAME AND ADDRESS DATA FURNISHED WILL ENABLE DEALERS TO FOLLOW UP WITH OWNERS INVOLVED IN THIS CAMPAIGN. THESE LISTINGS MAY CONTAIN OWNER NAMES AND ADDRESSES OBTAINED FROM STATE MOTOR VEHICLE REGISTRATION RECORDS. THE USE OF SUCH MOTOR VEHICLE REGISTRATION DATA FOR ANY OTHER PURPOSE IS A VIOLATION OF LAW IN SEVERAL STATES. ACCORDINGLY, YOU ARE URGED TO LIMIT THE USE OF THIS LISTING TO THE FOLLOW-UP NECESSARY TO COMPLETE THIS CAMPAIGN. OWNER NOTIFICATION OWNERS WILL BE NOTIFIED OF THIS CAMPAIGN ON THEIR VEHICLES BY BUICK MOTOR DIVISION. (SEE COPY OF OWNER LETTER INCLUDED WITH THIS BULLETIN.) CHANGE OF OWNER INFORMATION DEALERS ARE TO USE THE DEALER COMMUNICATION SYSTEM (D.C.S.) TO PROVIDE BUICK MOTOR DIVISION WITH SUBSEQUENT BUICK OWNER INFORMATION. BY REPORTING A CHANGE OF OWNER NAME OR ADDRESS OF A VEHICLE IN CAMPAIGN STATUS OVER THE D.C.S., THE NEED TO SEND IN AN S-866 FORM FOR THAT VEHICLE IS ELIMINATED. TERMINAL INPUT INSTRUCTIONS ARE COVERED IN THE D.C.S. MANUAL UNDER SECTION 9, PAGE 9-J01A AND B. PARTS INFORMATION PARTS FOR THIS CAMPAIGN ARE TO BE OBTAINED FROM GMWDD. ONE WHEEL CYLINDER RETAINER BRACKET KIT, PART NUMBER 18013604 IS REQUIRED FOR EACH VEHICLE INVOLVED IN THIS CAMPAIGN. BECAUSE OF THE LIMITED NUMBER OF PARTS AVAILABLE AT THE TIME OF CAMPAIGN INITIATION, OWNER NOTIFICATION AND PARTS DISTRIBUTION WILL TAKE PLACE ON A REGIONAL BASIS UNTIL SUCH TIME AS AN ADEQUATE SUPPLY IS AVAILABLE. TO ENSURE THIS KIT WILL BE OBTAINED AS SOON AS POSSIBLE, IT SHOULD BE ORDERED FROM GMWDD ON A C.I.O. ORDER WITH NO SPECIAL INSTRUCTIONS CODE, BUT ORDER ON AN ADVISE CODE (2). TECHNICAL PROCEDURE USING PARTS FROM KIT PART NUMBER 18013604, INSTALL A WHEEL CYLINDER RETAINING BRACKET ON BOTH REAR WHEEL CYLINDERS USING THE FOLLOWING PROCEDURE: 1. HOIST AND SUPPORT VEHICLE. 2. USE A BRUSH OR SCRAPER TO REMOVE RUST AND DIRT BUILD-UP FROM AREAS 1, 2, AND 3 SHOWN ON FIGURE 1. 3. PLACE A WHEEL CYLINDER BRACKET OVER BRAKE PIPE WITH BRACKET FINGERS TOWARD THE WHEEL CYLINDER. REFER TO FIGURE 2. THE RETAINER BRACKET MUST FIT FLUSH AGAINST THE BACKING PLATE MOUNTING FLANGE WITH ALL FOUR (4) BRACKET FINGERS EXTENDING INTO THE HOLE TO GRASP THE WHEEL CYLINDER. IN SOME CASES, IT MAY BE NECESSARY TO REPOSITION THE WHEEL CYLINDER TO PROPERLY INSTALL THE BRACKET. IF YOU CANNOT PROPERLY REPOSITION THE WHEEL CYLINDER, BRAKE DRUM REMOVAL MAY BE NECESSARY. CONTACT YOUR DISTRICT SERVICE MANAGER OR THE ZONE OFFICE FOR INSTRUCTIONS REGARDING THESE ADDITIONAL PROCEDURES. NOTE: ZONE APPROVAL IS REQUIRED FOR THIS ADDITIONAL LABOR. 4. INSERT THE CLIP BOLT FROM KIT THROUGH THE HOLE IN THE BRACKET AND START INTO THE CLIPPED-ON NUT. USING A #8 EXTERNAL TORX HEAD SOCKET, TIGHTEN BOLT TO 6.72 N.M (60 IN. LBS.). THE BRACKET MAY TEND TO WALK INWARD DOWN THE AXLE TUBE AS THE BOLT IS TIGHTENED. WHEN THE BRACKET IS PROPERLY INSTALLED, THE GAP BETWEEN THE BRACKET AND MOUNTING FLANGE MUST NOT EXCEED 3MM (7/64"). REFER TO FIGURE 3. IF GAP EXCEEDS 3MM., REMOVE BRACKET AND REPEAT STEPS 2, 3, AND 4. 5. GRASP THE RETAINING BRACKET BY HAND AND TWIST. BRACKET SHOULD NOT MOVE. IF THE BRACKET CAN BE MOVED, IT SHOULD BE REINSTALLED, REPEATING STEPS 2, 3, AND 4. 6. REPEAT STEPS 2, 3, 4, AND 5 TO INSTALL A BRACKET ON OPPOSITE SIDE OF VEHICLE. 7. LOWER VEHICLE AND INSTALL A CAMPAIGN IDENTIFICATION LABEL. EACH VEHICLE MODIFIED IN ACCORDANCE WITH THE INSTRUCTION OUTLINED IN THIS PROCEDURE WILL REQUIRE A CAMPAIGN IDENTIFICATION LABEL. EACH LABEL PROVIDES A SPACE TO INCLUDE THE CAMPAIGN NUMBER, THE FIVE (5) DIGIT DEALER CODE OF THE DEALER PERFORMING THE CAMPAIGN SERVICE, AND THE DATE VEHICLE WAS CAMPAIGNED. THIS INFORMATION MAY BE INSERTED WITH A TYPEWRITER OR BALLPOINT PEN. WHEN INSTALLING LABEL, CLEAN THE SURFACE OF THE RADIATOR UPPER MOUNTING SUPPORT AND APPLY THE CAMPAIGN LABEL WHERE IT IS READILY VISIBLE. LIST CAMPAIGN NUMBER LIST DEALER CODE AND LIST DATE VEHICLE CAMPAIGNED WARRANTY INFORMATION DEALERS ARE TO SUBMIT EACH CAMPAIGNED VEHICLE AS A SEPARATE CASE ON THE ONE-LINE WARRANTY DOCUMENT, FORM S-764. DEALERS SUBMITTING WARRANTY CLAIMS BY TELE-TYPE TERMINAL ARE TO TRANSMIT COMPLETIONS AS A SEPARATE CASE. FAILURE OPER. LABOR OTHER SUBLET OPERATION COUNT PART NO. ALLOW. CODE NO. HOURS HOURS MTL.TWG INSTALL BRACKET RETAINER KIT 1 18013604 * 96 V2860 .4 ** - *LIST CURRENT DEALER PRICE PLUS 30% OF KIT 18013604 **.1 HOUR FOR CLERICAL ADMINISTRATION.

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.