Vacuum lines + 4x4 = What the heck?! Help! :{
 

Previous owner tells me that if you "hook this line to THIS line, 4wd works great!"

...

Here's what he's talking about-

Everything:
Attachment 41073

Vacuum lines. One is blocked off with a *special* vacuum line block-off plug thingy. (AKA an old fuse. :D)
Attachment 41074

So this one is normally blocked off... this is coming from the electro(?)-pneumatic actuator on the front axle. This one is also blocked off with a *special* block off tool... the top of the strut.
Attachment 41075

You can see it disappearing to the front axle. (passenger side)
Attachment 41076


So... What am I missing? What component isn't working properly that it needs to be rigged?

I have a full service and diagnostic manual from Dodge, and I can't find anything on this system. Anybody know where to look?

LMK what other information I can get you guys to help me out.

Thanks!!!
-Andrew

You can bypass that stupid vacuum actuator and replace it with a cable system. much more reliable. You can spend all kinds of time and money to fix the stock setup now, only to have it fail again next month....

This might help.

Central Axle Disconnect (CAD) System Troubleshooting

Thanks for the 411, Chevy.

DaveO, you are the MAN! Gonna give that a good read and try to figure it out. If it looks like too much trouble/money, I'll go a different route. I'm trying to sell the truck and I want it done right.

---AutoMerged DoublePost---

Just sayin... this diagram REALLY helps..
http://mopar.mopar1973man.com/cummin...d/vac-diag.jpg

Quick question:

http://i110.photobucket.com/albums/n...esizedVent.jpg

Is that the vent?

Glad I could help. If you can't get it to work right, the posi-lock is a good choice, I installed one for a buddy on his suburban. As far as your question, I'm pretty sure that is the vent.

Thanks again.

I crawled under the truck and took some more pics and figured out where everything is going.

Turns out, the line that is blocked off on the strut is Tee'd into not only the Gray/Supply-to-Vac-Switch, but also the Green/Vent. Suspect?

Pics:

Labeled everything:
Attachment 40993

Unrelated... just for reference:
Attachment 40994

Revised:
Attachment 40995

You can see it from underneath. The line that "Disappears" goes to the green, and is Tee'd into the Grey/Supply.
Attachment 40996
Attachment 40997
Attachment 40998
Attachment 40999


Whatta'yall think? Vac switch?

The one you have labeled vent in the top picture I think is actually supposed to go to the t-case switch (grey in the diagram).

That's what caught my eye too, because the Grey and Green are Tee'd together. Didn't seem right to me. Vent should be it's own line, grey should be it's own line...

In this picture you can kinda see what I'm talkin about...

Attachment 40985

I just called O'Reilly's... A new switch is $9. Maybe they did all this "tee" action because the switch went bad.

What I plan to do (And I'm open to suggestions, here...) is to run a brand new line from the green vent line to the vent.

Shown here:
Attachment 40986

Then I will make sure the Grey line is coming from the line that I have listed here as "Vent" -
Attachment 40987

And see if that does the trick!
Any other ideas? :ouch:

Looking at the diagram, there's the green line (vent) from t-case switch, and then there's a little black line labeled as t-case vent that looks like it may tee in. Maybe that's what that is.

As far as the switch goes, for 9 bucks it's probably worth trying. Also replacing that grey line isn't a bad idea either. That way you'll know for sure what you have.

10-4. Good lookin' out, daveO.