Master cylinder question

I have a 2005 Taurus. I replaced the rear brake shoes and then bled the brakes. I have done both processes many times in the past on different vehicles. Afterwards, I had almost no brakes. I am aware that a master cylinder can give out during the bleeding process if it was weak to start with. Therefore, I replaced it with a rebuilt unit. When I took the old one off, I noticed that the fluid drained out of it when I disconnected the brake lines. When I installed the new one, the fluid drained out the brake line connection holes almost as fast as I could pour it in. I have never seen this happen on other vehicles before. This isn’t normal is it? I’m thinking I received a bad one from the parts store. Can anyone shed any light on my situation? Thanks.

How does the new one work? Looks to me like it should drain out:
BrakeMC