Qustion on proportioning valve brake lines

[deepockets]

I think I've got it figured out, except what to do with the port were I put the red dot. My car was a drum brake set up and I'm putting disc on the front. It's a 1970 roadrunner. Any pictures would really help. Thanks.

[hawkeye]

It has a plug. FSM 5-38.

[deepockets]

Thanks hawk. I did find while waiting for a reply on this site a diagram that also showed a plug.

[ws23rt]

I'm not sure if this will help any because all I have to refer to is my 69 with disc brakes.

My safety switch is different in that the line from the master cylinder for the front brakes enters the switch at the top and just down from their branches to the two front calipers.
Just below the switch connection are two more ports (one on each side like above the switch). One is fed by the master cylinder for the rear brakes and the other goes to the proportioning valve and then on to the rear brakes.

In your picture your proportioning valve appears to be connected to the front brakes but not the master cylinder or the safety switch.  I also see no line going to the rear brakes from the safety switch.

Your question raises one from me. ----Is a proportioning valve sometimes used in line for the front brakes to increase the line pressure for them? As opposed to how mine is---In line to the rear brakes to reduce the line pressure?

[deepockets]

I don't know much on this myself. The rear line isn't hooked up yet, but cleat on where it goes. there's also a line that goes from the bottom block to the top block that's not hooked up yet, but I'm clear on where it goes. Here's a print I found on this site.
http://www.forbbodiesonly.com/moparforum/attachment.php?s=c469c1523a7bcd66fbd0ebda59b668a8&attachmentid=117727&d=1368721822

[deepockets]

Oh, after watching a video from the ram man, He says that you don't need the 3rd valve that's about a foot back on the frame. Heck I don't know, that why I'm asking away!   

[1974dodgecharger]

mine are all used up and I have the same setup.....I will double check, but I believe you need lines for front brakes....so one from master cylinder into the prop. valve and 2 outputs for the front dics setup and one input from master cylinder and one output for the rears....so all 4 are used in a front disc setup?

[deepockets]

That would be great. Thanks.

[1974dodgecharger]

That's really weird now I know why it threw me off, but that line the bronze prop looking valve that looks like a triangle I don't think you need that?  That line from your driver front brake can go directly into the orange sticker tab that's how mine is.....

[new2muscle]

 You have a late-style safety valve, so you dont need the rear brake limiter (its built into the valve).

You DO need that upper valve for the front brakes, The upper port of that valve goes down to the upper front port of the safety valve. The back upper port (with the dot) is plugged.

Look at the FSM pg. 5-38. It fricken confusing, but all these valves have a purpose. That page shows three valves, but you have the later style that only has two. That upper valve is the pressure metering valve. It holds off the front brakes to allow the backs to bite first. Keeps the back end from wanting to swap ends.

Steve