I have a green vacuum line that run from T-case, up towards the firewall, along with the red and black CAD lines. The only difference is the green line has a rubber connecting end but is just hanging out not attached to anything. Can anyone explain what this line is for?

Thats the vent for the vacuum. It has a hose so it won't get plugged with mud (if it were just vented on the side of the transfer case it would be plugged in no time). It is supposed to run up to around the back of the engine somewhere and just hangs there. I assume you know the black/red are for CAD engagement and the white or grey is vacuum supply.

--- Update to the previous post...

Here we go. The curved lines are actual vacuum lines and the actual colors of them.

Thats the vent for the vacuum. It has a hose so it won't get plugged with mud (if it were just vented on the side of the transfer case it would be plugged in no time). It is supposed to run up to around the back of the engine somewhere and just hangs there. I assume you know the black/red are for CAD engagement and the white or grey is vacuum supply.

Thank you, I have seen a few posts about it being a vent but no one sounded sure of it. That is good to know. The rubber connector at the end is purely to protect the line/hose? And, yeah I was having some troubles early on with 4wd... It would shift into 4x4 but when driving with it engaged it would clunk (I believe in and out of 4x4) I have pulled the carrier, all bearings, axles has been disassembled and re-sealed on both sides, along with CAD clean up. My actuator may be going bad? I don't think there is any vacuum leak either. Everything else works fine including cruise, AC/heat.

I coulda sworn I wrote an article on this. Hmm, I will make one for Mike for future people :smart:Yes the thing on the end is to help it keep everything out. You can just take the actuator off and see if it goes all the way in and out with vacuum on either line.

Geez... Feel the love... At least you could of paint my truck the right color...

Now I feel better...

Hey thanks for the picture. How much does he charge to rent out that steamer anyway? Hah. I'm gonna check the movement with the cover off here today or tomorrow. Is the vacuum strong enough to pull and push vacuum without the rubber clamps on CAD lines?

Hey thanks for the picture. How much does he charge to rent out that steamer anyway? Hah. I'm gonna check the movement with the cover off here today or tomorrow. Is the vacuum strong enough to pull and push vacuum without the rubber clamps on CAD lines?

I was wrong on that cover thing. I had to look it up, I got a 2wd and was going by memory of the 4wd I did. You will just have to take the whole thing off and let it hang there and hook the lines up and go from 2 to 4 and see if the vacuum actuator works. There is a pic of the "cover" haha, you see why it won't work like I originally thought. You mean the compression clamps? Most of the vacuum lines I see don't have any clamps at all on them, the plastic lines just have a little rib on them to hold the line on.

I got to thinking and when you put it in 4wd it is not always lined up with the splines, so when you drive the splines line up after the wheel barely turns and then it drops in and maybe that is what you are hearing. The one I messed with wasn't audible though.

I got to thinking and when you put it in 4wd it is not always lined up with the splines, so when you drive the splines line up after the wheel barely turns and then it drops in and maybe that is what you are hearing. The one I messed with wasn't audible though.

When it was happening I did have a vacuum leak at the time, and that very well may have been the transfer case shifting in an out of 4wd because it was losing vacuum so fast but gaining it back upon acceleration. Causing it to shift in and out, making a very audible "clunk". I really haven't been able to test the 4wd thoroughly since the repairs. I've only needed to use it for a few seconds at a time since then.

When it was happening I did have a vacuum leak at the time, and that very well may have been the transfer case shifting in an out of 4wd because it was losing vacuum so fast but gaining it back upon acceleration. Causing it to shift in and out, making a very audible "clunk". I really haven't been able to test the 4wd thoroughly since the repairs. I've only needed to use it for a few seconds at a time since then.

Vacuum actually has nothing to do with the transfer case itself. The vacuum switch goes to the top and something in the transfer case just pushes on the bottom of the switch like a push button which switches vacuum from the red to the black vacuum line or vice versa. It sounds like you have something going on inside the transfer case itself.

Vacuum actually has nothing to do with the transfer case itself. The vacuum switch goes to the top and something in the transfer case just pushes on the bottom of the switch like a push button which switches vacuum from the red to the black vacuum line or vice versa. It sounds like you have something going on inside the transfer case itself.

I wish I could be more sure of where the noise was coming from, I believe the front axle but who knows. Unfortunately I need to do some seal work on both my tranny and my t-case, they have developed small leaks. I will be doing some more testing soon to narrow it down further. Thank you for all the info on this. It has definitely helped me, hopefully someone else can use it too.