Does anyone know where I can find a schematic of the proportioning valve used on 67 ss with front disc brakes.

What exactly are you meaning. The way the lines are routed or a internal parts diagram? You are talking about the one that sits below the M/C for 4 piston calipers?

Red 67L78, I am referring to the one that sits to the lower driver side of the MC and I would like to have an internal diagram as mine has a slow drip out the rear from the shaft that I need to fix before I lose all my paint. It must have an o-ring or some type of seal in it. Thanks in advance for any help you can give.

I have an assembly book for the J52 option. Does not give me internal diagram. I would probably buy a new one for this. Thinking trying to find internals for that, i would think would be difficult. I have seen from time to time these for sale on ebay. Book shows # 3905525 as valve assembly.
Also can buy new. I just don't know if you are going for originallty. But paint is expensive to redue.
Charlie

I believe HBC and other vendors sell a rebuild kit yes here is a link to the new website...search for prop valve if it isn't direct.

http://store.heartbeatcity.net/store/search.asp

Not sure how easy it is to get the large shallow hex nut off without rolling the edges over...never tried it for that reason...

Good link
$30.00 rebuild kit
$70.00 they rebuild yours
$124.00 for new one

Don’t tell anybody what a cheap redneck I am, but I had one leaking years ago before repro parts were around much. I took it apart, cleaned it and used a valve stem seal in it for the seal. It worked fine and never leaked again. :D

Don’t tell anybody what a cheap redneck I am :D

OK won't tell anyone ;)

Thanks for all the input, I think I will remove it, tear it down,(hopefully springs and etc. will not come flying out) and probably put a rebuild kit in it. Surely can't be a lot in that small of a package. Thanks again, John---:D proud original owner of a 67 RS and of a going back together 67 RS/SS 350:D