I went to bleed the brakes after bench bleeding the master cylinder. I started gravity bleeding the back 2 wheels
(drum brakes). Watching the master cylinder, after a little bit the level goes down,I top it off, then close the bleeders,
and start on the front passenger side (K&H 4 piston disc brakes). The master cylinder drops a little bit then stop's,
Before too long,I get out the mighty vac and start pumping. Next thing I know, all air is out of passenger side,no
air just brake fluid (I'm thinking life is good). I start on the driver's side, pumping my hand off no fluid. I call my buddy
an  auto mechanic,to help me.He's pumping with the brake pedal no fluid out of the drivers side caliper,I take the
brake line off of the rubber brake hose no fluid coming out. I put a new master cylinder, and 70's distribution block and proportioning valve for disc brakes.I take the brake line off at the distribution valve still no fluid coming out. There is
a nut between the brake line and the porportioning valve I take that off .We get a lot of fluid when the pedal is pressed,I tighten the nut back ,no fluid again,I ask my friend shouldn't there be a copper washer between the nut
and  distribution block,I didn't have any that would fit, but my friend did. By the time he came back,I checked
on the internet sure enough all pictures show a copper washer between the nut and the block. 3 pump's later
I had a full brake system. I will be calling the vendor I got the block from, to tell him to, check what he's selling.
so some poor soul doesn't have to go what I went thru. THANKS TO ALL FOR YOUR HELP ! mustang stu