Proportioning valve question

[6677ebman]

Have several used ‘’76-‘77 proportioning valves, and I know they seldom go bad, right?? Just to be safe, need to soak one in some brake fluid right?? Put disks on a ‘75, haven’t put the valve on yet

 

[DirtDonk]

If you're at the point of buttoning the brakes up already, I'd just drive it without the prop valve to see what you think.
If you're waiting for it so you can finish plumbing though, I would still take it apart and look inside.
They might look fine outside, and no they don't fail that often. But they can fall prey to rust inside. Just like any other brake part.

Pull the warning lamp switch out, pull the delay valve out (nipple thingy with the rubber boot over it) and pull the plug out of one end so you can see if the shuttle piston can come out or is stuck inside.

In other words, do a thorough inspection rather than just soak it. Let some light inside to see what crawls out.

Paul

 

[jckkys]

Mine looked good on the outside, but the inside needed work and replacement parts. Muscle Car Research has replacement seals and springs to restore the valve. Here;https://www.musclecarresearch.com/content/1979-gm-kelsey-hayes-combination-valve-autopsy. I found a few internal hard parts were corroded badly and had to get several junk yard valves to get good parts. Ford, GM, AMC, and Chrysler all used the Kelsey-Hayes valves. You find them in 70's and 80's cars and trucks all over the junk yards.