I have 79 f150 with rear disc kit installed. Looking for proper prop valve

 

There is no proper proportioning valve, disc brakes were never installed on the rear of an F-series. You need to use an adjustable P/V.

 

I'm gonna bump this and build on it...

I know a lot of people are going to rear disks recently and I will be soon.

I'm wondering if there is a stock type proportioning valve off of a stupid duty or something similar that people have used with luck when converting?

I am switching to a hydroboost at the same time and will be keeping the stupid duty master cyl. as that is meant for rear disks.

I was planning on running the in cab, adjustable proportioning valve, but I'd like to know if someone else has had luck with one off of a different year/model?

 

Myself...I would probably try and adapt the Superduty Proportioning Valve...It was designed for all wheel disc...don't see why it wouldn't work.

 

That was my thought Dave. Just wanted to see if anyone had already done it and liked the results.

If I can't find anyone who has done it and liked it - I may have to try it and post up!

 

Do you happen to have the Ford part number for this specific to F(Stupor Duty) only "Brake Differential Proportioning Valve?"

There is no such thing listed in my 1980/89 or 1990/2002 Ford truck parts catalogs.

 

I don't. I'd be the one to go to an autoparts store and have them look up "proportioning valve" for a 2002 F-250. No I don't know eactly what it is but that is what my hydroboost and master cyl. came out of so I'd be tempted to try it and see how it worked.

 

I would just grab one from the junk yard....If you need one I can look the next time I go to the self pull yard!!

 

Sure - why not. It's been forever since I've made it to a yard - so if you see one on a rear disk truck - grab it and I'll pay ya for it plus shipping!

 

Wouldn't it have metric fittings ?

 

I take offense to that, Steve. I used an adjustable on mine but my buddy left the stock one in place on his Blazer when we did it and it works just fine. Trial and error seems to be the way most go about it but I like the SUPERDUTY idea.

 

Nothing "super" about um hahahahaha

Stupid duty might have metric fittings - never though about that. Gotta love the retards at Ford going over to metric.... Oh well - it is what it is and I will have to figure it out. Everything else on my truck is custom - so why not the entire brake system as well

 

That whole magic combo with this entire thing is just that, magic. Identical trucks with the same components have had different results.
In fact the last time I was messing with this, I tried several combos, and ended up using an adjustable one. Much easier this way.
Some late cheby trucks had a Disc/disc set up and the biggest issue was the master cylinder. Some times the small reservior can run out of fluid and then the brakes are introduced to air, and they fail. Disc/disc masters have a common sized reservior front to rear, or simply one huge reservior. This seems to be the hot ticket when the piston is capable of producung the correct amount of fluid and pressure.
There is another option, some E-350 vans had rear disc brakes. Short school buses (you know some of you know exactly what I am talking about) and cab and chassis vans with a single rear wheel had rear disc brakes. These master cylinders and prop valves are pretty good to use, but they can be spendy and difficult to find used.
I have left stock prop valves in and been successful, so this is still magic. Sometimes something works and other times the exact same recipe does not work so well.
The one thing that works every time, is the adjustable valve.
Nice to be able to compensate for different loads, and even terrain.
Adjustable is easy and effective.

 

This was not Ford's idea...at all.

Our Government mandated that the US change to the metric system, and Ford was the last automaker to fully implement it.

 

What about this one ? Ebay#290347808464. Nobody ever answered if the late model prop valves might have the metric fittings.