Master cylinder/Prop valve problem?

[MrGoodpliers]

I put disc brakes from a '71 on my '69, and while I was rigging up my lines I took the fitting off of the back of the proportioning valve to the parts store so I could get the right fitting. A bit of stuff was in there, I'm guessing residual valve parts . Anyway, I think I have it back together the way it was but I can't get any fluid to move through the rear of the master cylinder. I took the line off the prop valve and blew air through it, lines not clogged. Pressing the pedal with the line off, I can hear air/suction but no fluid. Any ideas?