PV71 proportioning valve operation

[JTT]

I did the first test drive of my '65 Dart vintage racer project today. Otherwise everything was fine, but the brakes were heavily rear biased. Rear wheels locked long before the fronts.

The car has 4-pot Kelsey Hayes discs at front and 10" drums at rear. The master cylinder is from Mancini Racing: http://chucker54.stores.yahoo.net/ma1bowioutmo.html and there is a combination valve of the type PV71 by Right Stuff Detailing.

It appears the combination valve does not work as it should. Also, it seems that it is not adjustable. I found a picture of its internals, and that got me a bit confused. There is a metering valve, but it is at the front circuit?

Any suggestions of how to proceed (before I'll fit an extra proportioning valve to the rear circuit...)?

 

[67Dart273]

????

 

[JTT]

Thanks for the picture. It appears that the repro valve that I have, is not identical with the original one.

Anyway, I'll dismantle it tomorrow to see what's inside...

 

[67Dart273]

If it were me, I think I'd see if you could return that, and get an aftermarket adjustable valve. Of course you'll need something for distribution from the new MC

 

[BillGrissom]

As suggested above, I installed an adjustable prop valve on the rear line ($28). As many do, I kept the factory distribution block as a "tee" for the front lines. You plug the rear port and put a 1/4-3/16 inv flare adapter in the top port. Use a 3/16" coupler to connect to existing rear brake line. All fittings are in bubble packs at Autozone. Search for posts here.

 

[JTT]

I ended up installing an adjustable Wilwood valve to the rear line, and now it works. Thanks for the comments.