I have had problems before bleeding brake systems, and sometimes have had to use the pressure bleeder, this helps to center the proportioning valve and allow the fluid to flow....or if you remove the brake light switch in the valve you can manually center it and try the vacumm bleed..don't touch the brake pedal after centering the valve until you vacumm bleed.

If the m/c went dry you will have to start(bleeding) from there and move to the wheels. If no leeks and still no pressure your m/c is bad.

Thanks to all who have written.  

I think I solved the problem.    I put teflon tape on the left front caliper bleeder screw, and that was the problem.  Air was getting past the threads.  I think the rebuilt caliper threads were a little worn.  I went out for a drive, and went 5 miles and the brakes were good.  The pedal always did go close to the floor, and still does.  I am going to bleed the whole system again (all 4 wheels).

Good to hear