I am trying to get my 4x4 working in my 1995 Ram 2500. The lines were off at the CAD I reconnected them but not getting vacuum. I checked on the passenger side of engine and they are connected by the PCV valve. The lines are ok going from the transfer case to the axle. I noticed a Red line that has a female type connector on the drivers side that comes out of the bundle way up behind engine above starter. Spent a long time trying to find somewhere it might supposed to go but nothing I can see. I am not getting any vacuum under the truck. I hooked my vacuum pump directly to the CAD and got the 4x4 light to come on. I would really like to find where I am losing vacuum pressure. I am also thinking of getting the manual cable that way can bypass the vacuum lines to get 4x4 working. Is there a main line that carries the vacuum and what color is it.

 

have a look here. Should help.

 

^ can't stress enough the diagram above. understand that it puts continuous vac on the feed line to the the tcase switch, which has 4 ports (input, 2wd out, 4wd out, vent). the tcase shifter transfers that vac to either the 2wd line or the 4wd line. so when you get over to the cad, you should always have vac on one or the other. vac on 2wd line disengages cad collar. vac on 4wd engages cad collar. no vac on either produces random results and indicates malfunction.

start at the engine and follow the vac one step at a time. the feed line to the tcase comes from passenger side bundle and around the rear of the engine. most of them get butchered up here. the vent line from the tcase also rises up in rear of engine and has a little check valve thing on the end. its easy to mistake this for a broken vac line.

the vacuum system is very fragile. after fixing it several times, you might want to replace it with the Posilok, or the cheaper Alloy version.

 

Or try a posi lok I like it works better and won't go in and out.

 

Thanks for the info. Now that I know where to look I'll try it again.

 

Is there an easy way to lock the CAD and leave it permanently locked? That would be like running with locked hubs. That would be perfect for me and how we use the truck.

 

Posi-Lok have a permanent lock kit... Kit#1100 I believe.

I've also heard that flipping the folk over pushes the collar further over, so it can't disengage no matter what the actuator is doing, but I'm not sure of this.

 

The posi lok physically moves and locks the fork to engage the axle won't drift in and out like the vaccum actuator.

 

Thank you!