red and black lines run (or used to run) from the cad, under the transmission cross member, up to the top of the t-case driver side.

locate the t-case shifter linkage. look above it to a vac switch with a rubber boot on top with 4 vac lines. 2 of those are the red and black. another is vent. another is vac source to the engine. you can remove it by gently pushing/prying upwards. its keyed with slots, and only fits back on one way.

 

thanks d! I believe I was in the right place earlier and just didn't know it. I was just looking at the posi lok also, if I don't figure it out soon I'll return the actuator and get the posi lok. The one question that the instructions didn't mention is what do you with with the vacuum lines once you don't use them anymore, just tie them up and be done with it?

 

Remove them completely, and plug the port up by the engine where the white line goes. Leave the switch in the t-case to plug that hole.

Leave the vent line from the cad though.... you WANT that one on there, run it up just as far as you can.

 

well I went ahead and replaced the actuater switch and still don't have any vacuum on the lines. There is definitely vacuum coming into the switch, just none coming out. I think tomorrow (or next time I get a chance) I'll replace the red and black vacuum lines between the switch and the metal lines. I guess I could have gotten a bad switch, but... maybe I'll try to rig the vacuum going into the switch like suggested and see what happens...

 

The metal lines are more likely to be the problem..... they like to rust out. But, you live in florida, so, if the truck has spent it's life there...... who knows.

 

I have disconnected the plastic lines from the metal lines and there is none going into the metal lines. I'm going to try and replace the lines coming out of the actuator, guessing they are both shot, and see if that gets ride of it.

 

Wonder if they are plugged up..... Sounds like you got a plan though. Give it a shot, see what happens.

 

wait a minute. stop jumping around!!!

you need to trace and test the vacuum from the engine (source) to the vac switch at the t-case.

then - test the vacuum coming out of the switch on the t-case. you've got to have vac on the 2wd port when in 2wd and vac on the 4wd port when in 4wd. don't leave the vac switch until you prove this to be true or false. the vac switch should change between the 2wd port and the 4wd port based on pressing the ball on the bottom of the switch. And the t-case should have an internal piece that presses that ball in.

 

+1......... Check it correctly or don't bother.

 

ok, so with the switch in my hand I can press the ball and get the vacuum where it needs to be. Put the switch back on the tcase and nothing. I'm guessing whatever is inside the tcase is messed up? If this is the case, does that mean drop the tcase and dismantle?