Prop./ Brake valve

[mrhotrod]

Try this site they can set you up with all your brake needs and parts

http://www.hotrodsusa.com/

Residual Valves: Residual valves are pressure valve use to retain pressure in the lines.  The most common use is on a hotrod when there is a floor mounted brake pedal and master cylinder.  Mounting the master cylinder (M/C) below the floor positions it below the calipers.  Gravity will cause the fluid to flow away from the calipers.  The residual valve will retain pressure within the lines.  (i.e. 2 pounds residual valve will retain 2 pounds of pressure, 10 pound will retain 10 pounds.)  Drum brake master cylinders have residual valve(s) built into the master cylinder.  This is needed to maintain pressure against the cup seals in the wheel cylinders.  If you are using a disc brake master cylinder or after market you will need to install a 10 pound residual valve for the drum brakes.  Do not install a residual valve if your master cylinder already has one in it.  This will cause the brakes to lock up after the second application to the brake pedal. 

Distribution Blocks or Combination Valves:  One of the biggest misconceptions is the distribution block or combination valve.  Almost every factory car has one.  This usually serves as a metering block to adjust the proportioning to the rear brakes, as a "T" fitting for your front left and right front brake lines and brake light warning switch.  What people fail to understand is that each car is "engineering" for a specific distribution block based on weight, braking characteristics and tires.  So generally most factory cars have different blocks.

Save yourself some headaches install a adjustable proportional valve in the rear brake lines.

[jacks62440]

My car is not running yet so I can't say it works,  I have a 62 Savoy with 76-79 B- body 11 3/4" brake set up.  2 bolt Alum. MC.  I bought from Rick Ehrenberg. Adjustable brake rod from MP. A nice shiny alum distribution block off a Jeep Cherokee that had disks on the front and drums at the back from the wreckers. I am basically using the alum. distribution block just for connections. I have a MP adjustable proportioning valve ready to go into my rear brake line mounted on the frame with the knob sticking through the floor by my seat. That is mainly for ease of adjustment and so No one can mess with it.  Like I said the car is not on the road yet, but I think the System is Sound.   Jack

[b569rr]

This is a combination distribution block and proportioning valve from Stainless Steel Brake Company. it will set you back about $130. Placing it under the car per someone's suggestion frees up space near the headers.

Tom

[CrazyD]

what's the part number stamped into the factory brass version of the valve?

[Rick_Ehrenberg]

I strongly advise against using that old cast iron stuff. Just leave the stock brass safety switch tee unmolested, and install an adjustable valve anywhere in the rear line. Adjust it on a damp road so that the fronts lock just before the rears.

The metering valve is kind of useless for most of us. It's also called a "standoff" valve, the purpose was to hold off applying the front  brakes until the rear shoes had overcome the return spring pressure, to prevent low-speed front wheel lockup on glare ice!

Rick Ehrenberg

[Rick_Ehrenberg]

Residual Valves: Residual valves are pressure valve use to retain pressure in the lines.  The most common use is on a hotrod when there is a floor mounted brake pedal and master cylinder.  Mounting the master cylinder (M/C) below the floor positions it below the calipers.  Gravity will cause the fluid to flow away from the calipers.  The residual valve will retain pressure within the lines.  (i.e. 2 pounds residual valve will retain 2 pounds of pressure, 10 pound will retain 10 pounds.)  Drum brake master cylinders have residual valve(s) built into the master cylinder.  This is needed to maintain pressure against the cup seals in the wheel cylinders.

Virtually any Mopar wheel cyl mfg, after 1975 uses either high duromoter plasticized piston cups, or "expanders", so RP valves are redundant. Every Mopar M/cyl mfg. after '75 DID NOT have RP valves.

Of course, if, as MrHotrod says, you have a 'rod where the m/cyl is lower than the calipers or wheel cylinders.... ;->

Rick Ehrenberg

[jwmotors]

Why can't you run your rear line straight from the master cylinder port to the back where you split it to the wheels and run the front to the line lock and use that for your tee ?

[Broglock]

Just got done referring to a '77 service manual and they are still showing both the brass and cast combination valves (warning switch/ hold off or stand off / proportioning valve) for both the Volare and Aspen models  this year. Both pictures look very similar the blocks pictured here.
I had one question here are proportioning and hold off valves needed when you are running the same type brakes front and  rear. ie either both drum or both disc.
I had just figured to go after market with the valve since many brake vendors now offer them.

[moparrr07]

Why can't you run your rear line straight from the master cylinder port to the back where you split it to the wheels and run the front to the line lock and use that for your tee ?

because if you do that with no prop valve, the second you go to hit the brakes, the backs will lock up, a prop valve reduces the pressure to the back line, most guy do what you said but they add an adjustable valve in the rear line

[jwmotors]

The drum brake dist. block was not a proportioning valve, it is a t on one end and just a single line on the other end built into a brass block that also held the safety switch that would activate the brake warning lamp on the dash and on a drum brake car you do not need one and your wheels won,t lock up as far as disc brakes I don,t know how the brakes would respond without one .

[oj]

Here's one.

I need one of the brass prop valves like ski posted a photo of in the worst way. Does anyone have a lead on one of these? I can't find one anywhere! 
Bob

[69 GTS Clonvertible]

Ok, anybody plumb in the rear adjustible prop-valve after the brass distribution block but under the drivers door? I really don't want to have to lift my car to adjust the prop valve if I stick it directly after the brass distribution block. So I was thinking of cutting the line and adding the adjuster there. I would need to use a double flaring tool to flare the cut ends correct?
Can somebody knowledgable get me a quick answer as this is all I have to do to pretty much finish.

[jwmotors]

More fuel for the fire , if you are building a drag car or a car with big fat rear tires you would put the valve on the front brakes so you can adjust more pressure to the rears . The valve does not increase pressure it allows you to adjust the ratio by decreasing the line pressure to the brakes it controls .

[moparrr07]

right but even so 70% of braking is done by the front so if you have skinners and slicks, it would about even out with no prop valve

so with a normal front tire and larger rears then you would want to decrease the rear pressure,

its not like you will be locking up the fronts first if you have a decent rear brake setup

[75Dart440]

Ok, anybody plumb in the rear adjustible prop-valve after the brass distribution block but under the drivers door? I really don't want to have to lift my car to adjust the prop valve if I stick it directly after the brass distribution block. So I was thinking of cutting the line and adding the adjuster there. I would need to use a double flaring tool to flare the cut ends correct?
Can somebody knowledgable get me a quick answer as this is all I have to do to pretty much finish.

I built a mounting tab on the subframe connecter and mounted my WilWood prop valve about 8 inches behind the trans crossmember.  I can almost lean out the car door and reach underneath the car to adjust it!!

[69 GTS Clonvertible]

Ok, anybody plumb in the rear adjustible prop-valve after the brass distribution block but under the drivers door? I really don't want to have to lift my car to adjust the prop valve if I stick it directly after the brass distribution block. So I was thinking of cutting the line and adding the adjuster there. I would need to use a double flaring tool to flare the cut ends correct?
Can somebody knowledgable get me a quick answer as this is all I have to do to pretty much finish.

I built a mounting tab on the subframe connecter and mounted my WilWood prop valve about 8 inches behind the trans crossmember. I can almost lean out the car door and reach underneath the car to adjust it!!

That's what I'm going to do unless I plumb it to come up between the door sill and the drivers seat so I can adjust it without having to stop and open the drivers door.

[Stroked68Dart]

One more question for you guys:

I have a stock 68 dart with 4 wheel drums. 

I have installed Willwood front and rear disk brakes (13 inch up front and 12 inch in back).

I still have the stock manual master cylinder for the 4 wheel drums and the stock brass distribution/warning light block and all the stock lines.  All the stock parts are like new as this is a very, very low mileage car that I have now put a 402 cubic inch motor in.

My question is this:

1.  If I take out the residual valves from the master cylinder can I use that with my new disk brakes?

2.  Can I still use the stock distribution/warning light block as long as I put an adjustable proportioning valve between the brass distribution block and the rear disk brakes?

As always your guys help is greatly appreciated and needed.

You can see pictures of some of the work I have done on this car at www.billchatfield.com

 

[moparrr07]

ill answer # 2

you can leave it in their, but you put on some high buck brake kit, i would just pull it out, t the front and plumb the rear to the adj prop valve, i would pull it off and make it look nice, why leave factory parts in their if they are unneeded with 4w disk?

[jwmotors]

http://www.strangeengineering.net/catalog/index.html

Here,s some info some might find useful on the great prop. valve debate

[oj]

 I have found a porp valve from a Jeep Grand Cherokee that is almost identical to the 73-76 a body piece. But I think it is for 4 wheel disks. Can I use the Jeep piece with an adjustable valve in the rear drum brake line on my Duster, which has disks on the front? Eventually I will install 4 wheel disks on the Duster but that will be quite some time. If the Jeep piece will work for now it would save some trouble latter.
Thanks

[moparrr07]

if you put in the jeep one, plus an adjustable one, thats a double prop valve, just put a t on the front lines and an adjustable valve on the rears, no combo valve

[75Dart440]

I left the drum brake valve in (used only as a T for the front and pressure warning light for the dash that way).

Here is a picture of the Wilwood unit i mounted to the sub frame connector under the drivers door.

[69 GTS Clonvertible]

I left the drum brake valve in (used only as a T for the front and pressure warning light for the dash that way).

Here is a picture of the Wilwood unit i mounted to the sub frame connector under the drivers door.

Thats almost how I mounted mine, and the same goes for the stock distribution block I left it in.

[75Dart440]

I think it works well in that location.     I can lean out and reach it without leaving the seat.  Car stops good so far and I haven't yet made any adjustments to it!!  Took the car out on Sunday for a few street striping sessions though!! javascript:void(0);
4 speed

[Winter]

Better late....Here are some pages from the 1974 Manual. I use the Fig.1 for the 68 cuda, sold as "1972 manual disc master cyl., Duster" it has no residual valve in the rear outlet like the one in Fig.1. Willwood .81 rotor thickness on the front and 10x2.5" drums/rears, I use the 7/8" wheel Cly.(normal 15/16",with cups) without cup expanders to cancel rear brake lock ups at the finish line (brake games in bracket drags). The simple brake switch/warning needs to be removed, so the system has less to crode, and add the tee, that you guys are using instead. I don't think I need any adjustable proportioning valve, due to the smaller wheel cylinders.
http://i260.photobucket.com/albums/ii11/winterland959/BrakeWarningSw.jpg

http://i260.photobucket.com/albums/ii11/winterland959/MasterCylChart.jpg

http://i260.photobucket.com/albums/ii11/winterland959/FuryNoResidualMasterCly.jpg

http://i260.photobucket.com/albums/ii11/winterland959/Wheelcylinders.jpg

http://i260.photobucket.com/albums/ii11/winterland959/PropValveNoMeter.jpg

I've  run it without problems this past year, I will see if I need to change anything after a few more drag events.

[JoeSwinger69]

That new block is nice!
I just put a tee on the fronts, bought a $39.00 adjustable valve for the back and tossed the old stock block. Seems to work just fine. Just lacking the brake warning switch.

 After checking how the stock one worked, it got tossed !   That's how mines done.

                                                                   SIKPUP

I'm liking this idea more and more; the warning light is almost useless, anyway. If you wanted to get picky, I guess you can always add a gauge. I'm assuming that this setup works fine using stock size wheel cylinders out back?

  I did this and used a line lock then I wired the warning light to activate with the line lock, I did this cause I have a on/off toggle for the line lock under the dash and I couldnt remember wich way was on.