[rhandwor]

It sounds like the vacuum booster is going bad. Loosen one bleed line at a time on the master cylinder. Make sure you are getting pressure at this point.
Did you you use the two hoses and bleed the master cylinder before you tried to bleed the brakes. If you have no pressure remove the master cylinder put it in a vise use the two rummer hoses and push in with a steel rod until the master cylinder is bleed.
Use a block of wood and have somebody press on the brakes engine running and you putting some pressure on the block of wood. If you don't get any pressure the brake vacuum booster is bad. You would require as much pressure as bench bleeding the master cylinder would take.
If this is bad use a couple of straight edges and measure the length. The rebuilt should be the same length. This is the rod which pushes on the master cylinder.
Remember anti locks may need a scanner to cycle the valves.