proportioning Valve for disc conversion

[mguesto]

I am open to suggestions and criticism here so fire away.

I will be starting the SSBC brake conversin on my 69 GTX in the next two weeks.

My GTX has only drum brakes so the prop valve should be changed or have an adjustable valve installed inline. I am not interested in leaving the drum prop valve on and adding the adjustable one in there.

I did manage to get one from a U PULL IT place from a 75 Dodge Pickup truck with disc brakes on it. That was the closest I could get. the mounting is slightly different but i think i could use it.
Has anyone used a prop valve from a truck with success?
I am leaving myself open to your comments. ( oh Boy)

Thanks for your help and consideration.

Matt

 

[fla 66 cuda]

I left mine in my 66 cuda and installed the adjustable in the rear line behind the brass block [i don't think thats a prop. valve drums don't have one] i could be wrong. I suppose what you got will work with some fabricating.[i was told long ago they [prop. valves] have different pressures that they work at] i don't know if i beleve that cause i used one from a van in my car with no issues.

 

[ga66mopar]

You should check out inline tubes web site, They offer new proportioning valves and they are not expensive. I used the brass valve for a 74 A body with disk brakes. This one is a direct bolt in to 66-70 b-body.

 

[moparmarks]

What master are you using?
A Tee for the front and a adjustable valve for the rear is one way
Use any disc cast port valve from any 72-up mopar. A,B C and E all use cast iron valve 72-up.
Can use a 69B brass disc valve for correct look.
Call SSBC and see what they recommend.

 

[ga66mopar]

What master are you using?
A Tee for the front and a adjustable valve for the rear is one way
Use any disc cast port valve from any 72-up mopar. A,B C and E all use cast iron valve 72-up.
Can use a 69B brass disc valve for correct look.
Call SSBC and see what they recommend.

I removed the three or four proportioning valves off of 73-76 a bodies and they all had a brass proportioning valve.

 

[snakeoil24]

You can buy reproduction brake boosters and master cylinders from MBM/Pirate jack for 200.00 for the combo and a proportioning valve for 80.00 witch will give you 70/30 ratio.

 

[moparmarks]

I removed the three or four proportioning valves off of 73-76 a bodies and they all had a brass proportioning valve.

Disc or drum? Drum used brass but I though the disc A-body went to the cast valve like the B/E's. I have a 73A in the yard but can't see the valve in my pic so I'll have to go look.

 

[ga66mopar]

There were all disc brake cars because I got the spindles also. I guess they must have used both but the yard I went to all of the disc brake 73-76 a bodies had brass valves

 

[moparmarks]

Naw you maybe right. I've been more of a B/E guy over the years. Been a while but thought the last set I pulled have the iron valve.

 

[ga66mopar]

It sure was nice to use the a-body valve because it was a direct bolt-in with a b-body brake lines even bolts to the frame in the same place.

 

[99ss]

I used the SSBC valve.. it wasnt real expensive and is a decent piece

 

[BeastlyBirdie]

If you got the Texas valve off a 2wd, I used one with no ill effect. I'd never do the add in adjustable, just seems funky. A proportioning valve does just that, directs the fluid. The pressure has to overcome drum brake springs, to engage the shoes. That means that x amount goes forward and aft. Oem had various ones on the trucks, 4wd has one line plugged, supposedly a different one between 1/2,3/4, and 1 ton, but, I've swapped them around, never seen a difference besides plumbing. I'm sure someone will tell me that I'm going to kill someone, my brakes will fail, etc, so- this is from my experience and if you try any of this, you're going to wreck and wipe out a family, twenty nuns, and the only honest politician in the world.

 

[mguesto]

I appreciate the input on this, when i did my dart, i used a prop valve from a 73 also. direct bolt on and it has been
working fine since 04. I might have to look for one off of a 73 like Mark said above. If this does not pan out. I will
go back to online and get one of theirs that match for the $85 or so.
When i was at the junk yard, i got one off of a 70 Fury with power drum and the 75 pickup. both were around $12 each.
can't beat the price, but i want no problems afterwards.

I have done worse spending 30 or so on stuff i never used, The Fury was a brass block and the truck looks like it might be iron.
Thanks for your input.

Matt

 

[Rems440]

I used a adjustable prop block from summit racing when i added front discs,works great!

 

[68 Sport Satellite]

I have an aftermarket brass prop valve from the master power brakes kit that I installed when I added front disc on my '68 Satellite. I also added the Wilwood adjustable in line with that.

Whatever you do, after it's all installed, take your car out on an open wet parking lot and do a couple of 25mph panic stops. Adjust prop valve as necessary to eliminate rear fish-tailing. I did this with mine and was surprised how much the adjustable valve helped control this.

In a way though, I would rather have no proportioning valve. If we were to do disc brakes all around, would the proportioning valve be altogether eliminated and if so, could it still do a rear fish-tail?

 

[moparmarks]

Color me silly. 73A does have a brass valve. Funny that they went to the cheaper iron valve on everything but the A's.

- - - Updated - - -

If we were to do disc brakes all around, would the proportioning valve be altogether eliminated and if so, could it still do a rear fish-tail?

When doing 4-wheel disc I just Tee the fronts but run the backs through an adjustable valve. You want a 60-40 ratio.

 

[67 coronet]

factory drum brake systems use a diverter block.all it does is split the fluid flow,no proportioning at all.any 70/30 prop valve will work for the street,when switching to frnt disc rear drum.i prefer adjustable to the rear so i can fine tune my braking bias,as i drive my cars very hard.both systems will work fine,even aftermarket prop vales will work.adjustable rear valves just give you the added adjustment most aftermarket brake systems could use.

 

[mguesto]

i got the prop valve off today, that was brass and i will be making yet another purchase. I will replace the front lines that go from the prop valve to the frames and from the master to the prop valve.
After 40 plus years. I had some time to get them off.
Some got rounded off even using the line wrenches and others were marred from previous owner's work. PB Blaster helped a lot to free up some of the fittings. The master Cyl came from InlineTube, and i forgot to get the adjustable brake pedal rod.
That spiral armor protection was pretty filled with dirt and junk.
more pictures as i progress on this.

Matt