Ever had self adjusting brakes overtighten?

Interesting.... looks like both springs on the left are upside down vs the way they are installed on the right side. ....I’ll fix that but not optimistic that the total fix will be that easy since both sides are getting too tight. The previous posts give me a lot to look at. I also have a new master cylinder and parts on hand to rebuild the front brakes. I did the back brakes first because I was replacing the right rear wheel bearing last month. I can’t swear to it - but I’m pretty sure that the rear break lines were replaced back around 2007 when I first got the car back on the road and had some brake issues that I didn’t know how to fix. Now that I’m retired - I want to work thru this myself. Guess I getter quit putting springs in upside down. :-(
when you say you replaced the back lineS, I take it you mean the hard lines on the axle housing. But what about the rubber flex line from frame to axle tee fitting?. Those can deteriorate internally and act like a one way check valve. It usually happens at a strain point. I've never seen it on a rear axle flex line, but I've seen it twice on front brakes on Darts about 20-25 yrs old. Your Duster is almost 50yrs old.