71 demon brake questions.

Ok guys. i have a 1971 dodge demon. Originally drum brakes all the way around. did the disc brake swap with the 73 and later chrysler A body upper control arms and spindles, im using remaned calipers for a 79 plymouth volare and new 73 plymouth duster brake hoses. new raybestos manual master cylinder, all new brake lines, using an oem combination valve. heres the problem, when i go to bleed the brakes i start to get pedal but after the bleeder valve has been opened and the pedal goes to the floor to bleed the air out and after i close the valve and then pump the brakes theres no pedal unless i pump it up. also after you start to get pedal and let it sit then try to pump it again it goes to the floor, is there still air in the system? im going to try and use a vacuum bleeder tommorow and see if that helps, any other ideas would be appreciated.