WHEN BACKING 2004 TOYOTA SIENNA LE VAN IN DRIVEWAY THE BRAKES FAILED. THE VEHICLE HAS 41,000 MILES AND HAS ALWAYS BEEN SERVICED BY TOYOTA. THE BRAKES WERE CHECKED AT 34,388. THE CAR HAS A HIGHER IDLE (FUEL CONSUMPTION) SO IN THE PROCESS OF BACKING, THE CAR WAS ROLLING. I PUT THE CAR IN REVERSE AND DID NOT TOUCH THE ACELERATOR. THE VEHICLE ROLLED AND CONTINUED TO PICK UP SPEED, SINCE I WAS UNABLE TO STOP THE CAR. THE BRAKES WERE APPLIED AROUND 3 TIMES AND THEN I OPTED TO HIT THE RETAINING WALL INSTEAD OF GOING BACK INTO THE A BUSY STREET WITH WIFE AND CHILDREN IN THE CAR. IT WAS EITHER PRAY FOR NO COMING TRAFFIC OR RUN INTO THE NEIGHBORS HOUSE AND VEHICLES. WE HAVE NOT EXPERIENCED ANY PROBLEMS IN THE PAST. THE DEALERSHIP WAS UNABLE TO IDENTIFY ANY ROOT CAUSE. WE ARE CONCERNED ABOUT THE SAFETY OF THE VEHICLE AND WANTED A COMPLAINT AS A MATTER OF RECORD. IN RESEARCHING THE INCIDENT IN GOOGLE THIS IS NOT AN ISOLATED INCIDENT AND THERE HAVE BEEN A FEW RECORDS OF SUCH CASES WITH THE SIENNA VAN AROUND THIS MAKE AND MODEL. *TR