master cylinder issues.

[ols0051]

I have a 79 mustang manual master cyl, on a 88lx. I have a 3/4 spacer for correct rod lenght. The master cyl I have is a reman from the local parts store. The problem is that it takes 4 pushes on the pedal to get it to build pressure. I bled the lines multiple times and the only problem I found was that the fluid drains back into the main resevoir.(like a fluid fountain)Is this right. I think the brake line pressure would maintain if it didn't flow back into the resevoir. Is this master cylinder screwed up?