2004 dodge ram 1500, can the power booster check valve cause the brakes to fail?

What is your question?

Brake pedal goes all the way to the floor. Changed rear brakes, master cylinder and bleed all lines extensively. Still no pedal, power booster maybe?

What makes this problem better or worse?

Nothing

How long has your 2004 Dodge Ram 1500 had this problem?

A few weeks