ON 8/2/18, WHILE DRIVING MY 2014 TOYOTA SIENNA VAN, BOUGHT NEW FROM A LOCAL DEALER WITH APPR. 89,000 MILES AND METICULOUSLY MAINTAINED FOR ALL SERVICE, I WAS DRIVING ON A CITY STREET WHEN THE BRAKES FAILED AFTER PUMPING THEM THREE TIMES. THE BRAKE FAILURE CAUSED MY VEHICLE TO REAR-END THE VEHICLE I WAS FOLLOWING. NO INJURIES, BUT THE VAN WAS TOTALED. NO CITATION WAS ISSUED BY NORMAN, OK. POLICE, ACCIDENT REPORT #2018-57682. PASSENGERS IN MY VAN WITNESSED THE BRAKE FAILURE.