190e brake problems
 

I have a 1984 190e. I replaced the master cylinder and now I don't have any fluid to the rear calipers. I'm not pumping any fluid out of the front port line that goes to the rear. I have fluid to the front two wheels. The brake gets hard halfway down. When I removed the original master cylinder the valve that sits in the master cylinder came out. The booster pushes the valve which pushes the master cylinder piston. When I take the master cylinder out and push the piston, fluid comes out of the front port. Is this valve supposed to fit loose like this? I'm wondering if the valve isn't pushing the piston in far enough. Is there anything that could have dropped in the booster? Any ideas?
Thanks,
Doug