1966 brake proportioning valve

[J_Speegle]

do the valves leak when car is just sitting or does peddle pres need to be applied?

Believe it depends on how bad the seal is and if there is a leak above the valve allowing air to enter the system

[Cobra66]

I have no affiliation with White Post, but I have had three sleeved and rebuilt by them. I have no issues with the two that have been installed in my cars. The other sitting in my tool box.  Excellent job and would recommend their work.

[Pat Hickey]

is white post the preferred rebuilder?
any feedback on Karps brake service in upland calif?

Jeff does great work over there at Karps.He did my Hertz and is doing my other Shelby.

[gt350hr]

  My father in law (rip) did mine 30+ years ago with a brass sleeve and it's still perfect.

[sg66]

do the valves leak when car is just sitting or does peddle pres need to be applied?

Mine started leaking while stored last winter. Not sure if cold weather contributed to it or not but it had been rebuilt by Whitepost and in use for 4 years with no leaks.

More details in https://www.saacforum.com/index.php?topic=10452.0

Also after re-reading that thread, I realized some of the o-ring testing I did with DOT 3 and DOT 5 showed only Nitrile o-rings would swell in DOT-3 which now that I think about it, would help seal the end cap and may be why Whitepost and others don't guarantee their valves with DOT 5 fluid.

[JohnHouston]

I have noticed an interesting phenomenon with these, particularly on ebay.  Apparently, if you take an old crusty, leaking one, put it in a blue and white box and leave it on a shelf for a while, it becomes an NOS one.  Sort of an automotive transubstantiation . . .

john

[gt350hr]

   Marty??