I kept a careful eye on the fluid level. I had changed fluid colors so that I new when the new fluid started flowing out the bleed valve - should have been no air in the system. In my experience, if there is air in the system, you can pump the brakes and you will eventually develop pressure. And I had adjusted the brakes so that the shoes 'just' cleared the drum. I am inclined to believe that the master cylinder did not get correctly assembled.
