PE88019 · PE
SERVICE BRAKES, HYDRAULIC Investigation
SUMMARY OF INFORMATION FROM MANUFACTURER:ON SOME 1988 C/K MODEL TRUCKSTHE BRAKE LIGHTS HAVE BEEN FOUND TO STAY ON AFTER THE BRAKE PEDAL HAS BEENRELEASED.IN A MAJORITY OF CASES, THE STOPLAMP SWITCH BEING MISADJUSTEDHAS BEEN THE CAUSE.OTHER POSSIBILITIES INCLUDE (A) BINDING AT THE EYELET OF THE BRAKE BOOSTER ROD AND ITS ATTACHMENT PIN AND (B) PEDAL MOUNTINGBUSHINGS NOT BEING PROPERLY LUBRICATED.GM BELIEVES THAT IF THE VEHICLEIS EITHER ACCELERATING OR TRAVELING AT A CONSTANT SPEED, AND THE STOP LAMPSREMAIN ON, A FOLLOWING DRIVER WOULD LIKELY FOLLOW AT A GREATER DISTANCEBECAUSE OF UNCERTAINTY OF THE ACTIONS OF THE VEHICLE IN FRONT OF HIM.GMCONCLUDES THAT THIS IS TRUE BECAUSE THERE ARE NO REPORTED ACCIDENTS WHEREIT IS ALLEGED THE BRAKE LIGHTS STAYED ON.TO THE CONTRARY, BRAKE LIGHTSWHICH ARE ALWAYS ON APPEAR ARE INDISTINGUISHABLE FROM NORMAL TAILIGHTOPERATION AND THEREFORE FAIL TO SIGNAL BRAKING/DECELERATION WHICH IS THEONLY FUNCTION OF THE BRAKE LIGHTS.APPARENT INFANT MORTALITY SUPPORTS THEPOSITION THAT NO DEFECT TREND IS DEVELOPING.ALTHOUGH THE ALLEGED DEFECTMAY OCCUR AT ANY GIVEN TIME (IT DOES HOWEVER APPEAR TO OCCUR AT ANY GIVENTIME EARLY IN THE LIFE OF THE VEHICLE), ONCE THE BRAKE LIGHTS ARE STUCK INTHE ON POSITION, THE LIGHTS REMAIN ON UNTIL THE BATTERY GOES DEAD OR THECONDITION IS OTHERWISE DETECTED AND CORRECTED.THE ALLEGED DEFECT AFFECTSONLY THE EARLY PRODUCTION 1988 MODEL VEHICLES AND GM HAS ISSUED A SERVICEBULLETIN ADVISING SERVICE PERSONNEL OF THE POSSIBILITY OF THE ALLEGEDDEFECT AND HOW TO REMEDY THE PROBLEM. #======