Is my master cylinder bad?

[Chad-1stGen]

I've been having a heck of a time bleeding my rear brakes so I decided to move onto the front.

After 1 push with the bleeder valve open I loose pressure to the front brakes and have to pump the pedal 5-10 times after closing the bleeder before I can open the bleeder again and push the pedal down. If I don't pump the pedal the next time I open the valve it moves very little fluid and after a few rounds of not pumping it moves no fluid.

I bench bled the master before putting it on.

[Chad-1stGen]

Well I replaced the M/C on a hunch and it eliminated the problem.