[88Stanger]

Ok, well i decided to order all new hard brake lines from classic industries, pre-bent for my truck.
Got them in and went ahead and installed them. Damn, its nice to use stuff already pre-bent.
So now here is what i have:
from POL i ordered their Power booster, Wilwood 1" piston master cylinder and disc to disc prop valve. I bench bled the Willwood master and got all the air out of it. Then installed the brake bleed tool into the prop valve (Like the one AussieinNC posted). I did need to remove the piston and re-install it to a position that is correct and allow the tool to be installed correctly, into the v notch as it should.
Then i installed all the brake lines from front to rear, front and rear systems including across the rear axle. The only items left not changed out is the rubber hose from the frame to the axle, which is brand new, but i checked it out and it appears to be working fine, not blocked.
After all this, i vacuum bled as much as i could, then had a buddy over and do the you push the brake, hold it and i open the bleeder. We did this and still at the rear, little to no pressure and the pedal does not go all the way to the floor, like the fronts do.
Now im really frustrated!!
So, i started the pressure test from the rear towards the front. I still was not getting the pressure i should, so i worked my way forward, still nothing.
So, what to do now. I took off the master cylinder with the prop valve attached and thought, i want to do a test, basically a pressure/bleed attempt with the prop valve attached, and dang, lots of air came out, so i kept bleeding it until all the air was done.

Could the air in the prop valve cause the issue?

This weekend im going to re-install the master and prop valve after i bled them both and give it a try.