Proportioning valve install or not?

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72dart

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I am in the process of installing the SSBC A 153 disc brake kit on my Demon with drums. I have one side done and will finish the other side if I can find time with all the family stuff I have to do. I am worried about installing the adjustable proportioning valve the kit comes with that is to be plumbed in from the distribution block to the rear brakes. It looks like I would have to shorten the brake line to make it fit and I am uncomfortable doing that under the car since I have no experience modifying brake lines especially on my back under the car. I am thinking of either deleting the proportioning valve and seeing how the brakes perform or I have another option I am thinking of. I was looking at a picture of the factory combination proportioning valve/distribution block for disc brakes and thought maybe it would fit in place of the drum brake distribution block without modifying the brake lines. Can someone help me decide on a good course of action to take? Thanks for your replies.
 
Take a piece of say 2" pipe as a mandrel and make an "S" curve out of the rear line just enough to shorten it to where you can now plumb in an adj prop valve.

Much easier than trying to get a factory valve to fit...
 
redfastback said:
Take a piece of say 2" pipe as a mandrel and make an "S" curve out of the rear line just enough to shorten it to where you can now plumb in an adj prop valve. Much easier than trying to get a factory valve to fit...
Click to expand...

I did something similar.

And, yes, you need the prop valve.
 
redfastback said:
Take a piece of say 2" pipe as a mandrel and make an "S" curve out of the rear line just enough to shorten it to where you can now plumb in an adj prop valve.

Much easier than trying to get a factory valve to fit...
Click to expand...

Thanks that is a good idea.
 
You can't skip a prop valve with disk and drums. The rears would almost surely lock up first (don't want). Conceptually, you could get very small rear wheel cylinders that would work w/ no prop valve, but probably not available and how would you know the proper size.

The reason you need the distribution block is that it also has an "imbalance switch" to check that both F & R systems have pressure. Too bad it is down low, so your prop valve must be down there after it, in the mud.

A "combination valve" for a factory disk car does have a prop valve, but not adjustable so might not match your brakes. It might also require re-plumbing. Bending the "S" to shorten the rear tube sounds simplest. It isn't hard to make brake fittings, even upside down. Just insure you buy a quality double flare tool, and always put the tube nut on before flaring (how would I know?). Easy to tell when a fitting leaks.
 
A cheap tubing bender from the auto store would probably work better than a pipe in a confined space. Here's one for $8 from Amazon.

[ame="http://www.amazon.com/Tubing-Bender-Copper-Brass-Brake/dp/B00NERB0FK/ref=sr_1_7?ie=UTF8&qid=1411786737&sr=8-7&keywords=brake+tube+bender"]Amazon.com : Mini Tubing Bender for Copper, Brass and Brake Lines 1/4" OD : Everything Else[/ame]
 
Keep in mind I was suggesting a piece of pipe. Maybe 6" long at best. I got my piece as scrap from a hardware store.
 
The disk combination valve is not a straight swap, some of the inlets/outlets have different sized threads.I assume that was done so you can't mix up the reservoir lines from the master cylinder, because it matters which one is which on the disk cars.
 
72bluNblu said:
The disk combination valve is not a straight swap, some of the inlets/outlets have different sized threads.I assume that was done so you can't mix up the reservoir lines from the master cylinder, because it matters which one is which on the disk cars.
Click to expand...


?? I swapped a disc combo valve directly numerous times in place of a drum valve. Hell I just did it yesterday in fact. All the lines went right into where the were supposed to. Looks like a factory set up under there.
 
abodyjoe said:
?? I swapped a disc combo valve directly numerous times in place of a drum valve. Hell I just did it yesterday in fact. All the lines went right into where the were supposed to. Looks like a factory set up under there.
Click to expand...

Hmm. Sorry, you're right. I think I mixed it up with an earlier, single pot master cylinder car. They used all the same size fittings. Too many cars.
 
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