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idahocountryboy

No 4 wheel drive, tracking Vaccum

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Ok... Researched this, but to no avail. This site is not working for me, but I want to see it http://mopar.mopar1973man.com/cummin...d/vac-diag.jpg So, in Texas, it rains and when it does it POURS!!! and when your 4x4 doesn't work it's not good in this odd soil. Started at the vaccum pump, has good suction there, tracked it too the T section on the fire wall (the grey/white line). This line has suction that is lookin like it goes to the T-Case... Then kinda disparages but I haven't put a lot of time into finding it from there. It's hard to get to the top of the T-Case... So then I went to the CAD (actuator) on the front passenger side of the axle. The CAD has no suction, so fallowed the lines to the drivers side of the transmission where they run on the cross member (steel tubes connect to the plastic tubes) No suction at the plastic tubes. (all test done with the truck running) So... how do I get a test to the top of the T-case? Any other ideas? Second... The CAD was rotating pretty essay, is that good?

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Well thanks to Mopar1973mans web site I got it fixed... http://articles.mopar1973man.com/general-cummins/39-transmission-systems/80-central-axle-disconnect-cad-system-troubleshooting This is the reference that is VERY good on how to follow/fix this issue if you don't have time/funds for the Posi lock system.

once again... Vacuum leak! It was on top of the switch on the T-Case, Black (4x4) supply line. Cut it off right behind the brake put it back on, put the hose pod back on the direction I found it, and every thing works!!!

Here you can see I took off the Pod (cap thing) with the four tubes going in it, and saw the broken tube.

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If you want to know what the pod looks like (like I did, and couldn't find a pic) here you are... NOTICE... Two notches on two adjacent sides of the black pod... those tell you which way it was (is supposed to be) facing. It just pulls off the switch, pull upward and wiggle it'll come off.

Posted Image

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ISX,I have that complete harness out of the truck if you want pictures. I am in the process of going to a positive lock on the CAD. I left the pneumatic switch in the TC though. Let me know and I can snap you some pics if needed. Glad OP found the problem!!Hag

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