Several things I noted when setting up my front discs/rear drums....if you're trying to use a conventional prop. valve, whether salvage or new it will complicate getting a complete, airfree system. Secondly, the adjustable prop valve should go into the rear circuit along with, but in front of the 10# residual valve.
I see no practical reason to seperate the front disc lines. Having set up a number of this combination, I quickly learned that the factory or salvaged multifitting prop valves were the cause of most, if not all of my bleeding problems.
I'll add that it is important to have the rear brake shoes properly adjusted and that sometimes you have to give the calipers and wheel cylinders a tap to dislodge stubborn air bubbles.
I designed my system so that I could adjust my brake bias from inside the cab. Have some pics in my webshots "shoebox" album. Having a firm pedal and well balanced brakes should be a priority. Hope this helps.
Dave
