TRAVELING APPROXIMATELY 20 MPH ON A SURFACE STREET I PREPARED TO STOP AT A TRAFFIC LIGHT. SUDDENLY THE ENGINE WENT INTO A FAST ACCELLERATION. I COULD HEAR THE ENGINE RACING WHILE ACCELLERATING. I ATTEMPTED TO BRAKE BUT THE BRAKES FAILED. ACCELLERATION WAS CONTINUING. I SHIFTED TO PARK IN ORDER TO STOP THE VAN. THIS SAVED ME FROM CRASHING. THE VAN WAS DRIVABLE AND SO I DROVE HOME BECAUSE IT WAS EVENING. I AM AFRAID TO DRIVE IT AND WILL NOT DO SO UNTIL IT IS CHECKED OUT COMPLETELY. I UNDERSTAND THAT DAMAGE MAY HAVE BEEN SUSTAINED BECAUSE OF THE METHOD OF STOPPING IT.