Proportioning Valve - can I make into a distribution block ?

[Jack Parmentier]

I did a 4-wheel Right Stuff disc/disc conversion on my '69 Charger last fall, but the rear brakes have never seemed to brake correctly. I'm using the front/rear adjustable valve, but it has never seemed to do very much. I think the proportioning valve from Right Stuff for disc/disc conversions they sent me was never the correct part, it looks just like a BLK246 valve from Inline Tubing.

My question is can I remove the spring and valve from the proportioning side of my current valve I have ( which appears to be for a disc/drum setup ) in order to defeat any rear proportioning & allow the adjustable valve to do it's job for my disc/disc conversion ? Does not seem to me that it would cause any issues since the distribution part and low-pressure switch are in separate sections of the valve.

Thanks....

 

[Kern Dog]

You could plumb the system without any "distribution block" at all if you want. In essence, the front brakes get a direct line from the master cylinder and the rears do too. You could GUT a distribution block too.....The downside is that in the unlikely event of a system failure of even one wheel, the whole system goes out.

 

[sam dupont]

can't answer the spring question, but how is the proportioning valve plumbed?

 

[Jack Parmentier]

You could plumb the system without any "distribution block" at all if you want. In essence, the front brakes get a direct line from the master cylinder and the rears do too. You could GUT a distribution block too.....The downside is that in the unlikely event of a system failure of even one wheel, the whole system goes out.

ok.... that's true.... but just wanted to try an easy fix by just unscrewing plug, removing the spring & valve on the rear proportioning side (see photo) and then re-installing plug, without replumbing it all.

 

[Jack Parmentier]

can't answer the spring question, but how is the proportioning valve plumbed?

....just like in photo above... master cylinder front/rear outlets to valve inputs, front output to front brakes directly, rear output to rear brake line after going thru adjustable valve then to axle distrib. block.... just like factory setup, except using rear disc.

 

[sam dupont]

Okay, I read it as you had installed a proportioning valve like the one below. Do the brakes lock up in a panic stop?

 

[Kern Dog]

You could do a test with it as you mentioned.
If no parts have to be permanently modified, that is great. You can determine for yourself if it works with no permanent change or wasted money. I do experiments all the time in the theme of satisfying my curiosity.

 

[Jack Parmentier]

Okay, I read it as you had installed a proportioning valve like the one below. Do the brakes lock up in a panic stop?

My setup looks just like the stock Mopar combo distrib/proportioning valve ( which I think it might be instead of a distribution block only ) .... and then an output to rear brakes uses just a universal adjustable valve to balance rears.... The goal should be a similar function as the Wilwood one you have shown.

Does not seem to lock up, in fact it brakes rather slowly all around in a quick stop. ( No air, bled many times )

 

[pnora]

On my 69 Charger I went 4 wheel disc and used the stock 69 4 wheel drum valve with nothing else. Car stops perfect. It is also manual brakes. I bought the Master from Cass [Dr. Diff.] and went by his recommendations. He said try it that way before adding and adjustable valves.

 

[Cheapsunglasses]

Okay, I read it as you had installed a proportioning valve like the one below. Do the brakes lock up in a panic stop?








View attachment 1627173

I second this proportioning valve

 

[Kern Dog]

On my 69 Charger I went 4 wheel disc and used the stock 69 4 wheel drum valve with nothing else. Car stops perfect. It is also manual brakes. I bought the Master from Cass [Dr. Diff.] and went by his recommendations. He said try it that way before adding and adjustable valves.

What we sometimes stumble onto is "natural proportioning" where the brake force is at the desired 2 to 1 ratio. This is the goal for a street car, to have the front brakes responsible for double the braking as the rear.
Andy Finkbeiner wrote about this in his book, B body upgrades.
Sometimes we look at these nice looking rear disc brake kits and are tempted to use them without knowing if they are right for the combination. I'm guilty of that. I bought the Dr Diff 11.7" rear brake kit in 2006 when I had the Cordoba 12" front brakes. I had front caliper sizes that resulted in a system that spec'd out to a 3.37 to 1 ratio instead of 2 to 1. The braking was always lacking. It never made me amazed despite the hardware being good stuff of a great size. I would have had better performance with smaller front calipers which defies logic.
In 2022, I swapped out the Cordoba brakes and installed Dr Diff's 13" front brake kit with caliper bores that were smaller in total area. The brakes now are better than they have ever been. NO proportioning valve either, it is properly configured with ....natural proportioning.
Some people are smart enough to buy their parts after doing some research and asking the right questions. I wasn't but I'm getting better.

 

[gkent]

Do the brakes lock up in a panic stop?

Unless you have ABS, absolutely !!

 

[gkent]

If you install that Willwood prop valve you need nothing else - out of the valve straight to the rear and out of the valve straight to each front brake.

 

[Jack Parmentier]

Just to update everyone, I removed the proportioning valve part of the "combo" disc/drum valve ( spring, plunger, seal ). Rear disc brakes now work alot better & I can adjust the rear balance now with the adjustable inline proportioning valve. Thanks for the help !