OK seem to have it taken care of. Reversing the front brake lines did the trick. Maybe these two threads should be combined?

Its a tandem master cylinder, the port(s) nearest the servo go to the back brakes, the port(s) nearest the front go to the front brakes.
There are two pistons in line. When the pedal is pressed the first piston is pushed forwards and pushes fluid into the rear brake circuit, as the pressure in that circuit builds the pressure of the fluid pushes the second piston forward operating the front brakes.
This method ensures that the rear brakes are always operated slightly before the front to maintain stability under braking.

That makes perfect sense Rhinoman, and that's exactly what the FSM says too. What gets me is that both the black plastic coated lines go to some kind of splitter (Proportioning valve?) attached to the frame near the pass wheel. It looks like from there, it divides them, front pass, and rear, but also divides them front /rear/ + front. Very confusing.  It does seem to work now, so that's what counts! Thanks all for you help and Eric, thanks again for the photo!

That makes perfect sense Rhinoman, and that's exactly what the FSM says too. What gets me is that both the black plastic coated lines go to some kind of splitter (Proportioning valve?) attached to the frame near the pass wheel. It looks like from there, it divides them, front pass, and rear, but also divides them front /rear/ + front. Very confusing.  It does seem to work now, so that's what counts! Thanks all for you help and Eric, thanks again for the photo!

Cool, I'm glad I could help. To determine if you need to install a proportioning valve, I'd suggest going out on an abandoned piece of pavement somewhere and get 'er up to about 35mph or so. Then, slam on your brakes as hard as you can. If the rear locks up and comes around hard, you may want to install an aftermarket prop valve. Spidertrax sells one for a Samurai application but it works just fine for us. I have one on my Green Sidekick because of rear disks.

-Eric

PS. the purple cap rox! EH? 

  Oh man, I am now tearing my hair out, what little I have left! Got on the freeway heading up to Rousch, and of course, the front brakes began to lock up again. I drove around yesterday evening for a half hour with no problems, but as soon as I got up to freeway speeds, whammo, did it again. This is after I changed the lines around. I was able to crack the front brake line loose at the MC and free it up, but I had to do that twice to get it home. Now I'm begining to wonder if this MC is just a bad one? Used of course, but it seemed to work fine on the bench. Once it cools off, again, I'm going to put my stocker back on. I give up.