Some cars are really fast on down hills. Specially if they are out of brakes. Make sure your brakes are fine before going downhill. One way that you can check if they are okay is by looking for some old lady crossing the street. When you find one, just drive your car at full speed at her. When you’re almost hitting her, hit the brakes! If they are good, the car will stop before hitting the old lady. This is how I check my brakes. I check them every day for extra security.