I hear ya shoprat; I have had all my fliud drain out of my system before and have nevr had to bleed a proportioning valve.
From what I understand they don't make the exact one anymore, I may end up going to a junk yard and locating one.
I could redo all the lines and everything but I don't really want my truck down that long since I use it all the time.
I may just try bleeding the whole system to see if that does anything, I am not exactly sure if the mech that worked on
my truck after the rear end fire drained all the fliud out or not. He's in another state so I can't take it back to him.
The whole brake system was redone about 5 years ago now, plus at the time it was converted over from drum to disc
in the front and is now power brakes. I'll let you guys know how it works out.
Kurt