AFTER BRAKING TO STOP AT RED LIGHT ON A HIGHWAY ON A HILL, KIA FORTE 2010 KEPT MOVING UPHILL AT LOW SPEED (5MPH OR LESS). BRAKES DID NOT RESPOND. CAR STOPPED AFTER HITTING BUMPER OF ANOTHER VEHICLE. BRAKES WORKED NORMALLY AFTER THAT, BUT CAR SOMETIMES ROCKS AFTER BEING PUT IN PARK.