THE JEEP WAS PARKED IN OUR DRIVEWAY FOR ABOUT TWO HOURS WHEN THE PARKING BRAKE UNEXPECTEDLY RELEASED, CAUSING THE JEEP TO ROLL DOWN THE DRIVEWAY, ACROSS THE STREET, DOWN AN EMBANKMENT AND INTO A CONCRETE PORCH. THE BRAKE HAD BEEN CHECKED BY A MECHANIC TWO MONTHS EARLIER FOR A SIMILAR SPONTANEOUS RELEASE WITH NO WORN PARTS FOUND OR ANY DAMAGE TO THE MECHANISM.*AK