Proportioning Valve Problems

1968FormulaS340 said
A bunch of those rear brake lines are 40+ years old. People never check them. Changing it would be a good thing even if your brakes were working fine.

And changing may just solve your problem.

Could be a win win situation.

It got a new one back in `05-ish but most of this "new" stuff is not worth dirt, so it may have already lived its life.