I have always been told that you should have whoever is pumping your brakes hold the pedal to the floor as you tighten the bleeder. It take more pumping the brakes than you would think to fill the lines in a dry system. I would get a lot of brake fluid and two other folks one to watch the level and one to pump like crazy. It seems to work better if they don't pump to fast though. Make sure all four brakes are adjusted first. It is better to over do the bleeding. If you don't get all of the air forced out it will move in the line uphill as it sits for awhile. That means depending on how it is sitting any air in the line could move back towards the master cylinder as it sits. The next time you try to bleed you will have to force all of the fluid ahead of the air bubble out before you get to the air.
