if pedal goes down to floor then it sounds like brake master cylinder needs changing, if pedal goes hard with little effect on braking then it is a vacuum fault,either servo or vac pump/vac pipework/one way valve that is at fault.[i take it you have checked fluid level in master cyl-ruling out fluid leaks,also a very badly worn wheel bearing can cause excess travel on first press of brake pedal!]
k, November 2009