Mystery part

[Joe M]

I stopped over my friend's garage this morning to check the progress on his latest project.  It's an "R" code 428SCJ 69 Mustang.  He has it on the rotisserie and has just finished installing all the brake and fuel lines.  On the brake line leading to the rear brakes, just off the master cylinder is some sort of valve or something.  It's made of brass and about 3 inches long and an inch or so in diameter.  When I first looked, I thought it might be from a line lock or something that someone had added in the car's drag racing days.  After looking a little closer I thought it might be some sort of additional proportioning valve or something.  It was there when we took the car apart and it looks factory.  All the pre-bent brake lines fit perfectly.  The replacement inner panel had a hole for the attaching bolt to fit.  Sure looks factory.  Any ideas what the function of this part might be?  Thanks guys.

[machoneman]

Does it look like any of these prop valves? (not including the aftermarket one with the adjustable knob).  All Fords of the era had some type of prop valve (be it a K-H type or Ford made...and they do look quite different) for balancing front/rear bias. It it's got a knob, it can't be OEM Ford.  Hurst line-lock valves always IIRC had the Hurst name engraved on the body. Maybe a pic?

http://www.mustangbrakeparts.com/products.asp?cat=15

[Joe M]

Thank you for the come-back!  It kind of looks like the third item down in the list so it must be a proportioning valve.  There is no knob on it. I always thought that the proportioning valve was integrated into the distribution block where all the lines enter and exit and the only time one needed to be added was if the car was being changed over to discs.

[machoneman]

Sure!

No, only later or certain models of that era had the 1 piece integral distribution and prop valve block. Since it's a resto, I'm sure he'll want to rebuild or replace that old block with exactly the same kind. Btw, there are pretty cheap rebuild kits he can find on the 'Net that have all new internals like the disc(s), gaskets, o-rings...given the internals aren't all rusted up.

Ford did some funny things back them. My bro has a gennie early 1970 Boss 302, Dearborn-built but I have a California built late 1970 Mach I. His gas tank's top looks normal, all metal, no holes but mine has this weird plastic plug on the driver's side top that bolts onto a 2" hole on the top. After some research it turns out that Ford was already doing gas vapor recovery stuff on 70's CA built cars. I had to plug mine up and make a new traditional gas vent ala' bro's Boss 302 as no parts were available to restore the CA vent system.  

In a similar vein, if one goes back to look at the link, why in the world I wonder did Ford need so many different prop valves just for one line of Mustang? Go figure.  

[ScotiaFE]

Over at the 428 Cobra Jet site there is a good bit of info on this part.
Scott even sells the parts to rebuild one. I've never done mine, I changed all my gear to
Hot Rod stuff. lol

http://www.428cobrajet.org/how-to.html
https://www.musclecarresearch.com/valve-rebuild-wagner

[Joe M]

Wow!  Good info.  Thanks a lot guys.  The part is the proportioning valve as pictured  on the 428 site.  I guess I'm just not used to seeing it separate from the distribution block.  Very true that Ford did some odd things.  I'm retired from Ford and in the 70s I worked in Cleveland Engine Plant 1 on the repair line.  I pulled a 302 engine down and it had one passenger head and one truck head.  The truck head had valve rotators on it while the other side did not.  Car making has changed a lot since then.  Thanks again.