At Barber over Memorial Day weekend I found the the car had very little happening on the back wheels under braking. Yesterday I got far enough down the fixit list to attack that. An obvious culprit would be the brake bias valve or ABS unit since the hard lines looks to be undamaged. Having known good parts available from the 96 car I started on swapping parts yesterday.
I hit a major snag when I found that the bottom fitting of the bias valve was damaged by being cross threaded. A new hard line is the right fix, but there’s no way I’m going to manage that by this weekend. So now I’m searching for parts to make a field expedient fix. I’m hoping to find about 12" of metric bubble flare line and a compression fitting that matches the line diameter. Then I can splice in enough to reconnect the rear line.
Judging by the fittings, the ABS unit lines and bias valve have been off before and whoever did it did not use a flare wrench (or get that fitting started correctly). The bottom fitting of the bias valve had what looks like solder wrapped around the line between the fitting and the flare to get it to seal. Now that is an interesting work around.
I’d say the bias valve is at least part of the problem. When I took it apart it did not have all of the parts that it should and the spring was very obviously not the right one (larger in diameter, longer, and stiffer). That is probably a good explanation for poor rear break performance.