REAR BRAKE CLUNK NOISE OR VIBRATION/PULSATION. GMC Truck GMC C Sierra

SUBJECT: REAR BRAKE CLUNK NOISE OR VIBRATION/PULSATION (INSTALL NEW REAR BRAKE ROTORS)

MODELS: 1999 CHEVROLET SILVERADO AND GMC SIERRA 15 SERIES MODELS WITH RPO JC5

CONDITION:

SOME OWNERS MAY COMMENT ABOUT A "CLUNK" OR "THUMP" NOISE COMING FROM THE REAR OF THE VEHICLE, OR A VIBRATION/PULSATION OF THE VEHICLE WHEN THE BRAKES ARE APPLIED. THE "CLUNK" OR "THUMP" NOISE MAY BE ONE PER REVOLUTION OF THE WHEEL. THE VIBRATION OR PULSATION MAY OR MAY NOT BE FELT AT THE BRAKE PEDAL.

CAUSE:

CONDITION MAY BE CAUSED BY THE BRAKE ROTORS MICRO FINISH OR DISC THICKNESS NOT TO SPECIFICATION.

CORRECTION:

REPLACE THE REAR BRAKE ROTORS ON BOTH SIDES (LEFT AND RIGHT) WITH NEW ROTORS THAT ARE WITHIN SPECIFICATION. USE THE PART NUMBER LISTED BELOW. REFER TO THE 1999 SILVERADO AND SIERRA SERVICE INFORMATION FOR ROTOR REPLACEMENT PROCEDURES.

PARTS INFORMATION:

P/N DESCRIPTION QTY 15712800* ROTOR ASSEMBLY 2

PARTS ARE EXPECTED TO BE AVAILABLE 10-15-98 FROM GMSPO.

*ATTENTION DEALERS: PLEASE REFERENCE GM SERVICE PARTS OPERATION (GMSPO) INFORMATION BULLETIN #98-307 DATED OCTOBER 20, 1998 FOR SPO SPECIAL RETURN PROCEDURE.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME --------- ----------- ---------- H0137 ROTOR ASSEMBLY USE PUBLISHED R+R OR REPLACE LABOR OPERATION TIME

FIGURES: 00 ATTACHMENTS: 00

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.