I just got done rebuilding my truck after an engine fire. I got everything running but the 4X4. The 4X4 vacuum runs from the T adapter on the passenger side of the engine that the ac vents run off of right? If the 4X4 vacuum line runs from there where does it go to the transfer case at? The only thing a I have found is a green and white line that are hooked next to each other on the driver side next to the transmission but they just end and don't hook to anything.

My 4X4 worked before the fire so it should just be a vacuum problem.

 

i'm not sure, but on the top of the tcase is a big rubber plug with 4 vac lines. 2 go to the cad, and the other 2 come up the firewall. one of those is the vacuum source, and the other is a vent that dead ends in the engine bay. see if you can trace those 2 from the tcase.

 

The line runs on the back of the driver side cylinder head, near the exhaust manifold. That the place most common where you will fine the plastic tube has melted.

 

White line is vacuum source for the 4x4 switch on the t-case. Green line is vent line. Comes from the switch, and just ends up near the back of the intake. There is usually a little cap type feller on the end. (not a plug, just tries to keep dust, and water out. may actually be a filter....)

 

Ok I hooked the white line to the branch where the cruise and a/c vents hook to but it didn't work. Cruise and vents work properly and I don't get wild vents. I hooked it there because I was going off of this diagram



Is there a diagram of exactly where the white hose is supposed to go? Is it visible enough for someone to take a picture? I looked but I didn't see anything on the back of the driver side head

 

Where does the other end of the white line go? Does it actually make it to the switch on the t-case?

 

I cannot see it but it goes to the top of the tranny/tcase. I can see it going to the tcase but didn't actually feel it. You think maybe it came off of the switch? Should it work if I run it off of that tree where the cruise is hooked?

 

Should be enough room to crawl under there, and have a look. (bring your arm with its three elbows, a mirror, and a bright lite, just in case though. )

 

Ok I'll check it out when the truck cools off. Will it work when it's hooked up to the tree or do I need to find where it's supposed to go?

 

All it needs is a good vacuum source. Doesn't matter where you get it from.