For 1990-2009 cars

# INTERMIT. PULL W/O HARD BRAKE APPLY DURING NON-ABS STOP

******************************************************************** REVISION 01/12/94

THIS BULLETIN IS BEING REVISED TO ADD THE 1991 MODEL YEAR FOR "C" AND "H" VEHICLES INCLUDING PART AND WARRANTY INFORMATION.

PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK 90-5-17 CADILLAC T-93-134 GM OF CANADA 315004R OLDSMOBILE 90-T-213 PONTIAC 90-5-19 *******************************************************************

#### SUBJECT: INTERMITTENT PULL WITH A HARD BRAKE APPLY DURING NON-ABS STOP ON ABS EQUIPPED VEHICLES (REPLACE ABS VALVE BLOCK/PRESSURE MODULATOR VALVE)

#### MODELS: 1986-90 BUICK ELECTRA 1988-90 BUICK RIVIERA 1986-91 BUICK LESABRE 1988-90 BUICK REATTA 1991 BUICK PARK AVENUE 1986-91 CADILLAC DEVILLE, FLEETWOOD 1988-90 CADILLAC ELDORADO, SEVILLE 1986-91 OLDSMOBILE NINETY-EIGHT, EIGHTY-EIGHT 1988-90 OLDSMOBILE TORONADO, TROFEO 1986-91 PONTIAC BONNEVILLE EQUIPPED WITH ANTILOCK BRAKES

SOME OWNERS MAY COMMENT ON INTERMITTENT PULL WITH A HARD BRAKE APPLY, BUT WITHOUT ABS ACTIVATION. THE INTERMITTENT PULL CAN BE EITHER TO THE LEFT OR RIGHT AND ONLY OCCURS WITH HARD NON-ABS STOPS.

THIS CONDITION MAY BE DUE TO A BASE BRAKE CONDITION, LOOSE SUSPENSION COMPONENT, OR THE ANTILOCK BRAKE SYSTEM. WHEN WORKING ON A VEHICLE WITH THIS CONDITION, USE THE FOLLOWING PROCEDURE:

1. INSPECT THE BASE BRAKE SYSTEM. CHECK FOR LOOSE OR BINDING CALIPERS, DAMAGED ROTORS, OR RESTRICTED BRAKE LINES. REFER TO SECTION 5 OF THE APPLICABLE SERVICE INFORMATION MANUAL FOR COMPLETE INSPECTION AND REPAIR PROCEDURES.

2. INSPECT THE SUSPENSION SYSTEM. CHECK FOR LOOSE CONTROL ARMS, DAMAGED STRUTS, OR BUSHINGS. REFER TO SECTION 3 OF THE APPLICABLE SERVICE INFORMATION MANUAL FOR COMPLETE INSPECTION AND REPAIR PROCEDURES.

3. IF NOTHING IS FOUND DURING THE ABOVE INSPECTIONS, REPLACE THE ANTILOCK BRAKE SYSTEM VALVE BLOCK, (PRESSURE MODULATOR VALVE FOR 1991 MODELS). FOLLOW THE PROCEDURE IN THE APPROPRIATE SERVICE INFORMATION MANUAL.

1986-87 C/H MODELS VALVE BLOCK . . . . . . . . P/N 25530880 1988-90 C/H MODELS VALVE BLOCK . . . . . . . . P/N 25533639 1988-90 E/K MODELS VALVE BLOCK . . . . . . . . P/N 1646523 1991 C/H MODELS PRESSURE MODULATOR VALVE. . P/N 25559182

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION NUMBER:

H2517 (FOR 1986-90 MODEL YEARS) H2480 (FOR 1991 MODEL YEAR) USE PUBLISHED LABOR OPERATION TIME.

FIGURES: 0

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 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.