1996 Silverado 1500, pulling to the drivers side when hitting the brakes.

I started trying to bleed the brakes and discovered there was no fluid getting
to the passenger caliper, (front brakes) so I replaced the soft line and tried
bleeding again. I had trouble but finally got fluid. It did fine for a short period
of time and then starts pulling left again, so I bought and replaced both
calipers, (unwise decision looking back now) and ways I can't get fluid to the
passenger caliper again. This time I started tracing the line, and got back to
the abs controller. It appears to have five lines. A larger and smaller diameter
line going in from the master cylinder to the controller and two small, and one
larger diameter line going out to the brakes. Looks like the larger of the three
lines goes to the rear, and the two smaller lines feed the front. I had some one
mash the pedal and hold it and I cracked open one of the small ones and got
fluid, so I repeated the process only I cracked open the other one, and
nothing. So I am guessing that there is no fluid pressure from the abs
controller to the passenger side. Now what to do to fix the problem. Help
would surely be great, thanks