So the break pedal was going all the way to the floor. I changed front rotors, pads and changed the fluid. The brakes worked great and the pedal felt great!....for 2 weeks. Pedal all the way to the floor again. What the hell....Master cylinder? Brake pump? Just need to do back brakes?

 

First bleed the breaks until only clear, bubble free, brake fluid comes out. If that doesn't help, pump the brake pedal a bunch of times with the motor off. If the pedal doesn't firm up then either one or more flexible brake lines is ballooning from the pressure or the master cylinder is bad. If it does firm up, then they are fine. Good luck...