My brake pedal randomly hits the floor..ABS kicks in...but still doesn't stop right.. I'm stumped on how the brake system, can allow, the pedal to hit the floor without loosing any fluid.. When the pedal hits the floor, either master cylinder is bad, or you got a leak somewhere.. Where does the brake fluid go when neither of those is the problem??. And more importantly, what's wrong with it?.. is it really the booster...?