NHTSA Complaint #10417833 — 2005 TOYOTA PRIUS

BRAKES ON 2005 TOYOTA PRIUS STARTED INTERMITTENTLY ACTING UP ABOUT A YEAR AGO, AFTER SIX YEARS OF NO PROBLEMS. OBSERVED SYMPTOMS WERE EXTREME JERKINESS OF BRAKE OPERATION DESPITE CONSTANT PRESSURE ON BRAKE PEDAL. SYMPTOMS OBSERVED AT ANY SPEED, BUT ESPECIALLY NOTICEABLE AT SLOW SPEEDS (COMING TO A FINAL STOP, SUCH AS AT A TRAFFIC LIGHT, OR IN REVERSE BACKING OUT OF DRIVEWAY). WHEN APPLYING BRAKES AT HIGHWAY SPEEDS, JERKINESS FELT LIKE ALTERNATE OVER BRAKING / UNDER BRAKING. SYMPTOMS WERE QUITE SCARY THE FIRST TIMES IT HAPPENED. HAD PERSONAL MECHANIC CHECK OUT BRAKES. TEST DRIVE CONFIRMED PROBLEM, BUT HE WAS UNABLE TO FIND ANYTHING WRONG WITH HYDRAULIC BRAKE SYSTEM. SINCE PROBLEM WAS INTERMITTENT, WE DECIDED TO SEE WHAT HAPPENED. PROBLEM CONTINUED INTERMITTENTLY, GRADUALLY INCREASING IN FREQUENCY TO THE POINT IN THE LAST MONTH WHERE IT WAS HAPPENING MUCH MORE OFTEN THAN NOT. TOOK CAR TO TOYOTA DEALER FOR DIAGNOSIS. PROBLEM WAS NOT EVIDENT ON DAY OF SERVICE. THEY CHECKED COMPUTER FOR STORED ERROR CODES, AND FOUND NONE. REAR BRAKE DRUMS SHOWED SLIGHT WEAR AND WERE OUT OF ADJUSTMENT, SO DRUMS WERE CLEANED AND TURNED AND BRAKES ADJUSTED. NO DIFFERENCE IN OBSERVED BEHAVIOR; BY END OF THE NEXT DAY, JERKY BEHAVIOR NOTED AS BAD AS IT HAD EVER BEEN. TOOK CAR BACK TO DEALER. THEY REPLACED THE STROKE SENSOR EVEN THOUGH THERE WAS NO STORED ERROR CODE. THIS APPEARS TO HAVE FIXED THE PROBLEM, SINCE THERE HAS BEEN NO RECURRENCE OF PROBLEM IN A WEEK OR DRIVING SINCE REPAIR. BRAKES FEEL TOTALLY NORMAL AGAIN, FOR THE FIRST TIME IN A YEAR. NOTE ON DIAGNOSIS PROCEDURE: THE DEALER SEEMED TO INITIALLY DISCOUNT MY DETAILED, WRITTEN DESCRIPTION OF THE PROBLEM, AND REACTED ONLY TO THEIR OBSERVATIONS. WHILE UNDERSTANDABLE, IT IS FRUSTRATING TO THE OWNER AND COULD LEAD TO A SERIOUS PROBLEM NOT GETTING FIXED. I FEEL THAT THE SYMPTOMS AS DESCRIBED TO THEM POINTED DIRECTLY TO THE STROKE SENSOR AND IT SHOULD HAVE BEEN REPLACED ON THAT BASIS. *TT