My daughter has a 2001 1.8 turbo GLX Beetle and there is a problem with the brakes. When you start the vehicle the brake pedal will go all the way to the floor and pressure will build then push the pedal up, even while you are still pressing, and will then begin to roll. The only way to prevent this from happening is after you start the car, is to pump the brake pedal a few times before putting in gear. If you do not do this, you will have not brakes. Any idea what is causing this?