Proportioning Valve

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GlennB4u

GlennB4u

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I upgraded to disc brakes from PirateJack on my 67 Barracuda and now have to deal with the proportioning valve. I bought a factory style distribution block with attached proportioning valve. Does anyone have a picture of how this thing hooks up? Does it require a jumper from the block to the valve?

propvalve.jpg
 
Here it comes
Orient the thing with the switch facing left and the long hex nut up.
Oriented thus, the port on top is from the M/C rearmost chamber to operate the front disc brakes. The two immediately below it go out to the front brakes.
The next one down comes from the M/C frontmost port for the rear brakes. And of course the lowest port goes out to the rear brakes.
The little pin you see sticking out to the left in your picture should have a boot on it to protect it from the elements,IIRC. I have not seen that outboard device on any 1972 to 1975 Combination valve.It kinda looks like a Metering valve. I seem to remember that valve being a separate valve on KH equipped A-bodies, from 68 to 72. It was plumbed into the front brakes. The idea was to slow down the application of the front calipers, to give the rear shoes a head-start.
My KH system doesn't require it. If you wish to plumb it in, then yes you would need to jumper it in. It would be the first to receive fluid from the M/C rearmost chamber for the front brakes.The outlet would then go to the TOP of the Combination-valve.
If you are gonna run 275s or better,out back, you won't need a proportioning valve if you install 13/16 or smaller rear wheel cylinders, and have 10" drums.
The safety switch is good to have, but in my opinion kind of a novelty, cuz when it lights up, you will already know all about the pressure imbalance going on. The block is however a convenient place to route all the lines from. I just gutted the proportioning part of mine, so the rear w/cs get full line-pressure.
I have 7/8 w/cs and cannot lock the 10inchers back there with 295s, on pavement.
 
AJ/FormS said:
Here it comes
Orient the thing with the switch facing left and the long hex nut up.
Oriented thus, the port on top is from the M/C rearmost chamber to operate the front disc brakes. The two immediately below it go to the front brakes.
The next one down goes to the M/C front most port for the rear brakes. And of course the lowest port goes out to the rear brakes.
The little pin you see sticking out to the left in your picture should have a boot on it to protect it from the elements,IIRC. I have not seen that outboard device on any pre 1975 Combination valve.It kinda looks like a metering valve. I seem to remember that valve being a separate valve on KH equipped A-bodies. It was plumbed into the from calipers. The idea was to slow down the application of the front calipers.
Click to expand...

Many thanks.
 
I believe this is pictured in the shop manual. You can download the 73 shop manual, free, from MyMopar. That manual, and some others, came from guys here at FABO

Somewhere along about page 5-18 -----5-20
 
67Dart273 said:
I believe this is pictured in the shop manual. You can download the 73 shop manual, free, from MyMopar. That manual, and some others, came from guys here at FABO

Somewhere along about page 5-18 -----5-20
Click to expand...

Thank you. I'm in the process of scanning my ancient Chiltons manual...ill share when complete.
 
A separate metering valve was not used on '73-'76 disc brake equipped A-bodies. If you knock the stud out of the mounting bracket and unbolt/remove the metering valve, you end up with a reproduction of the '73-'75 A-body 1 piece, brass proportioning valve. You can plumb it just like an A/B/E body drum brake distribution block:

http://www.forabodiesonly.com/mopar/attachment.php?attachmentid=1714562638&stc=1&d=1353309031

Otherwise, the E-body valve you purchased must be plumbed like this:

http://board.moparts.org/ubbthreads/upload2/2901851-PropValve.JPG
 
Almost the entire MTSC series is at www.imperialclub.org
go to Literature, Repair
Then Chrysler Master Tech Series
Scoll down or search for the pamphlets on Brakes starting around 1967. There are several that specifically describe which proportioning valve and when applicable, metering valve, goes with each system. Illustrated too.
There's also a good thread here o FABO where we straighten out a mixup in the FSM illustration of the 4 piston Kelsey Hayes with a Bendix proportioning valve.
 
My memory is failing so ignore me if I'm wrong here... Assembly workers and dealerships service techs has a special little tool that either pulled or pushed that little pin ( my memory says pulled ) a prescribed distance to center the prop' / spool valve. Without that tool it would be very difficult to get fluid flow to all the system, center the valve, and get the brake warning lamp turned off.
 
I thought they self centered when the brakes were back to snuff? The spool is usually pushed toward the back of the valve when its 'tripped"
 
DoctorDiff said:
A separate metering valve was not used on '73-'76 disc brake equipped A-bodies. If you knock the stud out of the mounting bracket and unbolt/remove the metering valve, you end up with a reproduction of the '73-'75 A-body 1 piece, brass proportioning valve. You can plumb it just like an A/B/E body drum brake distribution block:

http://www.forabodiesonly.com/mopar/attachment.php?attachmentid=1714562638&stc=1&d=1353309031

Otherwise, the E-body valve you purchased must be plumbed like this:

http://board.moparts.org/ubbthreads/upload2/2901851-PropValve.JPG
Click to expand...

I ended up removing metering block like you mentioned here. Works fine.
 
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