2010 Camry, I4. Heard snap while driving, pedal went to floor. Had some brake power but pedal always went to floor under moderate-heavy braking, drove home (no traffic, etc).
Assumed master cylinder. When I took the old one off, the "push rod" (not sure of the term - the thing the master cylinder sits on, which transmits force from the brake pedal to the master cylinder piston) inside the brake booster had play. That is, I could wiggle it up and down, side to side a bit. I assumed it should only move back and forth in the horizontal plane to push the piston.
Nonetheless, I attached the MC (since the old one was clearly leaking), assuming it might be fine. Bled it, brakes still go to floor (but I might need to bleed the whole system).
My question is - can the brake booster "push rod" be "loose" like I described or is that a clear problem?