1997 dodge vaccum pump/4x4 issues/exhaust brake issues
 

Hi everyone, Got a 1997 dodge 2500 with an pac brake vaccum pump exhaust brake the previous owner of my truck installed..Wrong.. So right now the AC will turn on same with heat and work but the directional switch to make it point to feet/vent/defrost is not working and my exhaust brake recently stopped working and now after all of this the 4X4 stopped engaging and the latest is now it will pop out of 2 wheel drive into neutral and cause me to completely disengage from the motor. Now the T on my truck on the vaccum lines one goes from vaccum pump to the T then to the acuator for the exhaust brake the other side of the T has nothing on it and i've plugged it. off the accuator for the exhaust brake it had 3 lines going off two to the actual exhaust brake and one hooked up to the T like i said earlier. Does anyone have any ideas to buying some new vaccum lines and where to plug em in? or should i be looking for new exhaust and taking the whole exhaust brake system off and restarting? Sorry i've seen previous threads for this but most of the trucks are so dirty i cannot seem to see the conections where the 4X4 plug in is on the front axle. thanks so much for the help!

See if this helps:
Mopar1973Man's Dodge Cummins Articles - Central Axle Disconnect (CAD) System Troubleshooting

New problem
 

Ok so i went out and bought that posi lock system and installed it but now its stuck in 4x4 so it did fix the problem of it slipping in and out of neutral but now its complelely stuck. When i installed it about half a quart of fluid came out of the differential would it help if i refilled the front diff or what do you think? the fork that pushes the gear back and fourth to put it into and out of 4X4 and 2 wheel drive its the gear that stuck not the fork so maybe fluid? or whats the next step if that gear is seized? taking the whole diff off? Thanks again for the help!

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Put fluid in it and nothing changed. If this gear is seized anyone know where to redirect me to installing a new one or maybe taking out the front drive shaft? the front axle still spins that part is just locked in 4X4

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Maybe lift the front and rear ends on jack or stands and see if taking the pressure off will make it easier to unstick the gear for the CAD? need help please. Any ideas.