After a slippery ride during our first snow of the year I've found that I have a broken or disconnected vacuum line on my 98 2500 4x4, so the front axle is not locking. This line comes from the transfer case and goes up the drivers side between the rear of the engine and firewall. I have two issues right now with this.

1. I can't find a loose vacuum line in the engine compartment to plug into.
2. the other line (wire?) in the picture appears like it may be a ground wire but not sure.

Any advise on where these are supposed to connect would be greatly appreciated.

Thanks,

 

It's flexible line from the CAD to steel to the back of the transmission then back to flexible line, one blk one red.

There is a larger line coming off the CAD to the engine compartment but it's a vent line and attaches to nothing.

I can't tell from the pic exactly where that line is

 

i'm not sure, but that might be the vent from the t-case.

a vacuum source goes from the engine to the top of the t-case, to a 4 line switch. the 4 lines on the switch are input vac, output vac 2wd, output vac 4wd, and vent. the 4 line coupling is key, or it only goes on one way, so you can pull it off and down to where you can look at it.

http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm

 

you should put in a posilok and do away with that vac line to the CAD all together. Some folks don't like it but I love it. It doesn't work off vacuum from manifold (I've got a vac leak that I have yet to find causing wild vents but that's another story) It's a pull cable that engages the fork in the CAD and eliminates your chance of popping that hose and loosing 4 wheel drive. Only thing I don't like is you have to rolling at a good clip (>5mph usually) to engage it. Check it out. http://www.4x4posi-lok.com/app_dodge.html
best thing about the posi is that you can drop into 2 wheel low and creep without being in 4 wheel drive. It's great for backing a camper/trailer and such.

The vacuum line going up in front of fire wall should not be open, it should be going to intake manifold. I was just looking at that tonight. On passenger side of intake manifold you have three ports about halfway back. One goes over to pcv on valve cover (passenger side), one is connected to Throttle body and evap canister and the third port will come out of intake and tee off and send one vac line to cruise control and the other will go to another tee and feed the climate control and the 4x4 axle. This link should explain that engine compartment end. Dhvaughan may have you squared away on the Tcase end of things. The van line going to CAD should use intake vacuum to engage/disengage explaining why you can't engage. hope that helps!

 

and here is the other link for the line diagram.
http://www.justanswer.com/dodge/2nie...-2500-360.html

 

I'll need to do some more investigating.
When I first saw this line dangling free I thought it was a good place to start but if it is just a vent tube then mounting it somewhere isn't going to solve my problem. I still wonder what that wire is bundled with it, it's pretty rigid like maybe 10 ga. Maybe it just had an eyelet for mounting the tube to the firewall.
As far as originating point for this line it's hard to say for sure since I can only trace it by feel but it does start somewhere on top of the T-case, so it starts at the T-case, runs forward on top of transmission, then starts to go up firewall on the drivers side and that's where is dangles free. The vent tube for the CAD is securely in place on the passenger side.
Not sure how much time I'll have the next few days to work on it so may be a delay here.

Thanks for the replies,

 

I've got a broken vacuum supply line. In the picture the line that has that elbow with what looks like a cap is a vent line. The other line in there is the supply line that should connect to the intake manifold on the passenger side (not directly but to a larger rubber vacuum line). This line in the photo was burnt on the end so it was hard to tell what it was so I cut a small piece off and saw it was actually a tube, then I traced the line from the intake back and found the same issue. I've never had to this type of hard line before so don't know if it can even be done. Will give napa a call to see what they have but if anyone has any suggestions how to patch this please post them.

Thanks,

 

I suppose the correct method would be to get the vacuum line from the dealer.

What I do when I can is just "sleeve" it with some rubber vacuum hose.

 

The sleeve method is what I ended up with. I want to Napa and the best fit they had was a rubber windshield washer line, it was really tight, so went with that. We still have some snow in the yard so I was able to confirm that the axle is locking. This will be good for now and then maybe when it warms up next spring I'll look at replacing with the original material.

Thanks all,

 

These might help..




This one is from a 97



This one is from a 98 2wd