Brake problem someone help please

[Thejman]

I have an 86 GN. Recently I had an issue with a leaking wheel cylinder. So like anything else I replaced it. At the same time I decided to bleed the brakes all the way around to make sure there was no air in the system. I ended up replacing the front calipers do to the fact that the bleeders were ceased solid. So everything back together and I am ready to bleed. I was told gravity bleeding was the best way to get a good pedal. I started with the rears and a full res of dot 3 fluid. Well I got side tracked and forgot about the bleeders being open. The rears completely drained out and the res was empty. So I filled it and then bleed the brakes doing the old pump it twice and hold while I crack the bleeder. Doing all this with the key off. So I get an even flow of non air rated fluid . I figured they were all set but when I got in the care turned the key the pedal was really soft and the brake light was coming on. And of course the pump was coming on every time I applied the brakes. I figured there was air in the master so I bench bleed the master in the car to make sure no air was in it. Got some bubbles out. Then repeat bleeding this time with the key on. Still the same results . If anyone else has ever had this issue and can lead me in the rite direction. I would greatly appreciate it. I was thinking it might be the proportion valve. But I can hear a hissing at the master when I pump the brake "AIR" . Not sure i just want to figure this out so I can hit the track this year.