Why do i have no front brakes?

[monstergarage87]

Well its intermittent... front brakes seem to just cut out. Rear brakes lock up and the pedal goes all the way to the floor. I have no clue what it could be. My buddy was looking at the booster while i pumped the pedal and he noticed the booster moving, not sure if thats normal. If anyone has any opinions on what it could be, let me know. Thanks, John

 

[pocket-rocket]

My initial thought would be master cylinder.