WANTED: Proportioning Valve

Joe,

Be aware they are different animals,

The shuttle (differential) valve activates when a brake circuit (front or rear) is compromised to illuminate the brake fail warning light and also prevents loss of fluid from the non compromised side to help safely stop the car.

The proportioning valve is a pressure limiter that helps balance braking front and rear to prevent rear wheel lock prior to front wheel.

Shuttle Valve Schematic

Proportioning valve

Joe needs the shuttle valve. I'm sure someone has one laying around that can help him...

I can't find it now, but wasn't it from Ford pick up truck. the rebuild kit I have list these Ford numbers
C7ZZ-2B257-A,
C7ZZ-2B257-C
C7OZ-2B257-C
C8OZ-2B257-A
C8ZZ-2B257-B
D0OZ-2B257-B

Someone has to have one laying around as many people have removed them when upgrading their brakes. Who's going to help Joe out?

Scott...I may still have my old one, I'll look in the morning.

Curt

quote:

Originally posted by ZR1 Pantera:
Someone has to have one laying around as many people have removed them when upgrading their brakes. Who's going to help Joe out?

I have one. please email rfmccall@comcast.net .

Ron

First, thanks to everyone for their posts on my need for a proportioning valve (and special thanks to Scott for his technical advice). I will be e-mailing Ron about the piece he has but in the meantime, this is what I've learned:

1) None of the Pantera vendors had a used proportioning valve but a large, reputable west coast Pantera parts dealer told me it was the same piece as on a '72 cougar or LTD (neither of which had rear discs)

2) I checked the orange pantera parts book and the part # is 2B257

3) If you search e-bay, there are several variations of part 2B257 available some with "A" "B" or "C" suffixes so JFB #05177's suggestion that the following might work seems to be accurate:
C7ZZ-2B257-A,
C7ZZ-2B257-C
C7OZ-2B257-C
C8OZ-2B257-A
C8ZZ-2B257-B
D0OZ-2B257-B

E-bay listings for 2B257:
https://m.ebay.com/sch/i.html?...1313&_nkw=Ford+2b257

One of the only differences I saw when looking at these listings is that the mounting plate can have variation (for pantera, two bolts go through the front trunk floor but some of the listings have three and some have one)

4) there are also vendors on e-bay that sell a proportioning valve that appears to be an exact duplicate of the pantera piece but they also indicate:
"V6070FD - 1965-1975 Ford Mustang / Falcon Proportioning Valve (Disc/ Drum) Also Fits 60's to 70's Ford Cars" - I asked Scott about these and he didn't think they'd work because of the "Disc/Drum" designation - take a look:
http://piratejack.net/1960-70s...proportioning-valve/

4) However thinking about the fact that the west coast pantera parts dealer told me it was the same piece as on a '72 cougar or LTD and neither these had rear discs, I think this part will work...

5) is it possible that Ford/DeTomaso just used the same piece for the pantera as on the cougar, LTD and other Ford offerings under the premise that the stock Pantera front brakes are so much more powerful than the rear discs (like the difference in braking between front discs on the '72 cougar and its rear drums)?

5) I am e-mailing Ron McCall now about the part he has available, but thought it would be interesting to hear everyone's input on this as if the pieces being sold on e-bay work, maybe this is a new source for everyone who needs a replacement proportioning valve...

Thanks again for the quick and helpful responses to my post - Joe

quote:

Joules

To clarify (and according to Joules' pictures above), I am looking for the brass shuttle valve under the brake booster/MC - sorry about any confusion

Yes and thus it makes no difference whether there are discs or drums. This is not a proportioning valve.