brake peddle almost hitting floor board

Look behind wheels make sure its not leaking out from a bad wheel cylinder if its not leaking bleed out line see if pedal comes back

If the lines to the breaks are clear of air and you see no fluid leaking anywhere at the break cylinders or in the lines and you can not "pump" the breaks to a firm condition, then the next suspect is the "O" rings on the master cylinder. Another culprit can be the vacuum assist drum with a leak in the drum itself or a bad check valve where the vacuum line attaches to the drum.