I'm in the process of troubleshooting HVAC and 4WD vacuum issues. I've got HVAC fixed by disconnecting the lines going to the transfer case so there is a leak somewhere. Anyway, the vac lines all appear to go to the top of the t-case, with not much room between it and the bottom of the body. It's pretty tight up there. Do you have to drop the t-case in order to get at these connections, switches, etc.? If so, what does that process entail?

 

No need to drop transfer case. It is a pretty tight fit but the vacuum lines connect to the switch just to the side of the transfer case. I used a flashlight to get a good view. Also a pair of hose pulling pliers to remove the hose connector(this has the three vacuum lines to it. Disconnect each hose one at a time and run new lines. Not hard to do, just have to be patient. I have had to do it twice because of atf in the lines. The connector has a hole to line up to the switch and can only go on one way. Line it up right and push it back on to the connector. Hope this helps.