Proportioning Valves

[Ricko1966]

It's been discussed several times here... a SEARCH would've shown this.
It's not just a proportioning valve, it's a "combination" valve.
It has the ability to warn the driver if there's a failure.
The manual ones can't do that.

The combination valve also has the standoff valve for the rear brakes.

 

[Ricko1966]

1000% on what you're saying, except that valve doesn't seal off a failed section.

They're inherently isolated. But I've never had a failure where the failed section didn't dump all the fluid.

They are supposed too. And sometimes they do.

 

[Ricko1966]

COMBINATION VALVE!!!!!

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[FreeTruck]

Bill I was seriously joking, I probably got a little wordy with my response and you thought I was serious.
LOL Keith

 

[Ricko1966]

Wilwood and others have more than one style of adjustable proportioning valve,depending on whether or not you are keeping your original combination valve and adding an adjustable in the rear line. Or using a distribution block with an adjustable valve,and if you are using 4 wheel disc,4 wheel drum or Drum/Disc you may need to add a residual pressure valve. Wilwood says to use one in the rear line on a disc/drum if you are losing the standoff valve contained in the original combination valve.

 

[Old Guy Bill]

Bill I was seriously joking, I probably got a little wordy with my response and you thought I was serious.
LOL Keith

No prob Free, I'm sorry for the misunderstanding.
The rear brake line has a larger thread than the two front brake connections on my valve. Not sure about the exact size.
The adjustable manual valves can work great, we always put one on the rear brake line on circle track cars that I could reach down and give it more or less rear brake.. depending on what was needed.

 

[Old Guy Bill]

Are all the ports on the factory one threaded for 3/8 - 24 fittings?

Here you go FreeTruck

 

[FreeTruck]

Wilwood and others have more than one style of adjustable proportioning valve,depending on whether or not you are keeping your original combination valve and adding an adjustable in the rear line. Or using a distribution block with an adjustable valve,and if you are using 4 wheel disc,4 wheel drum or Drum/Disc you may need to add a residual pressure valve. Wilwood says to use one in the rear line on a disc/drum if you are losing the standoff valve contained in the original combination valve.

That's good info to know. I'm going to have to replace mine as it's residing on that brace underneath the core support and it's cruddy as hell, about the only part of the truck besides the battery tray. I was looking at Willwood prop valves, so I guess I need one of those too.

Thanks for the pic Bill, that's the one I see everywhere online, but I read they may not be the most reliable.