Hello, I have a disc brake proportioning valve from a 1973 Plymouth Satellite and was wondering if this proportioning valve would work on a 1972 Plymouth Satellite that has disc brakes?

This proportioning valve(see pics below) is original to the 73 B Body. It is a Kelsey Hayes #89410.

Any help would be greatly appreciated.

Yup 73-74 P-valve good to go on 71-72 w/ disc brakes. . The one in your pic I think is from an E-body though.

Thanks for your info. But I'm most certain that this pv is original to the car (1973 B Body w/disc brakes).

Are the rear drum sizes the same? that'll vary the application as well

So 10" vs 11" drums would require a different pv? The one pictured above is from a 10" application.

IMHO 10" or 11" drums you'll be fine. The swap to larger rear drums have been done many times without any problems.

IYO maybe, the factory disagreed.

The job of the combination valve is to marry two substantially different braking systems, disc vs drums. Discs are fairly linear in application, self energizing drums are not. For example, my 87 M body had two different PV's available, the only difference in the braking system was 10" vs 11" drums. I don't plan to redesign the braking system so I tend to follow what he factory did when updating my brakes.

I would think it should be fine. Thats actually a combination valve that has the Proportioning valve and the Metering valve in it with the balance valve for the brake lite. I would try it and see how it works. Do some hard and light braking and see how the rear bakes act. The prop valve will limit pressure to the rear brakes on hard braking so the rear dont lock up and the Metering valve will hold the front brakes off on light braking until the rear reach a certain pressure or overcome the spring tension. Ron

383 you are right, but the spring tension is different between 10" and 11" drums, one of the difference, not to mention the kneepoint setting difference.

A decent write up, not too technical, but hits the high points.

http://stoptech.com/technical-support/technical-white-papers/proportioning-valves

I agree with you. But I just wonder if its enough for the average driver to notice a difference in how it brakes. Thats why I said I would try it and see how it acts. I have seen alot of guys change them around over the years and drive them even though it may not be right. I guess it worked good enough for some to drive. Ron

I dunno, maybe I am just a turd polisher

this is true. but, when you change or stagger tire sizes [think big & littles], it may be best to replace the factory valve with an adjustable aftermarket item. this may also apply to the pad/shoe material in use compared to the factory material, although to a differing degree i suppose.

Done it before with zero issues, I'll do it again. I'd only go A/M on the valve if I'm going the rear disc route.

My 65 runs a PP from a 5th ave.Been on since 99 and no problems.read an article years ago by a Mopar master cant remember who now.He said pretty much they will interchange as it dosent matter a lot.Many factory changes were mandated by feds etc.Rocky

An adjustable proportioning valve handles exactly ONE aspect of what a factory combination valve handles, proportioning and that is it. Thge factory combination valve does a whole lot more.

You do not want a combination valve with rear discs nor should you need one with a properly designed all disc system since the front and rear behave the same and you can adjust bias with bore sizing.

If you are going to the effort of junkyarding a combination valve why not get the right one and not one "close enough"?

No your just a perfectionist which is good and I try to be but sometimes it does make us think to much. Ron