By pushing you brake pedal to the floor (or letting it drop there), you run a significant risk of ruining the seals in your master cylinder. You normally never would push the pedal all the way down, so deposits form at the back end of the master cylinder bore over time. You ruin the piston seals when you force them over the deposits by bleeding this way.

When bleeding, you should first see how far the pedal goes down under normal pressure, then place blocks of wood, or whatever, underneath it so it doesn't go past this point when you bleed the brakes.

I hope you didn't damage anything, but I wouldn't be surprised if you need a new master cylinder in the near future.

GregS