ENGINE WAS STARTED ON THE VEHICLE. VEHICLE WAS PUT INTO GEAR WITH THE BRAKE PRESSED FIRMLY DOWN. THE VEHICLE STARTED MOVING EVEN WHILE BRAKE WAS PRESSED VERY FIRMLY IN. BRAKE PEDAL WAS ENGAGED AS FAR AS IT COULD BE, BUT THE TRUCK CONTINUED TO PICK UP SPEED UNTIL IT COLLIDED INTO ANOTHER PARKED VEHICLE. THE BRAKES WERE NOT WORKING AT ALL. IT CAUSED A CRASH WHICH CAUSED DAMAGE TO BOTH VEHICLES, MINE BEING A BENT UP BUMPER ON A 2 WEEK OLD TRUCK.