Well, after getting the replacement rearend in and back together, including bleeding the rear brakes, I now find that the MC IS leaking again - crap, this will never end!
I also read that over filling the reservoir can cause this, I also noticed that my rubber seal is not very uniform. I'll try to find out if I can replace just the rubber seal for starters - not sure if they sell them alone.
Gary, I don't remember anything about a "residual valve" from any posts. I may have thought that it was another word for "proportioning valve". But I had gotten to the point where I was chasing my own tail because I was totally lost. I'll try to look at the post and info at MBM tonight so I can see what you are talking about.
The only thing I haven't replaced is the proportioning valve. I'll post pix tonight of my prop valve, MC and booster, and lines.
Thx to all as always!
BTW, The new 3.89 rearend is fun! It's amazing what a difference it makes from a hole shot. I went out to a remote road and ran through the gears - speed shifting to second gear the tires spun and I got a lot of axle hop (chatter). Probably a good time to replace the 30+ year old shocks, and either replace or retention the springs.