2nd Gen Non-Engine/Transmission vacuum lines have gear oil inside?

[JAlford]

I have discovered there is what appears to be gear oil inside my vacuum lines. Is it possible to get axle lube from the 4x4 actuator into the vacuum lines? I can't see how it would get into the diaphragm area. Any ideas?
Jeff

 

[Bob V]

Somewhere around the 1999 model year Dodge "T"ed the vents for the transmission and the transfer case into the vacuum vent for the CAD system. I see you have a 2WL system. When that is engaged you will actually putting vacuum on the vent lines for the trans and transfer case. So it is possible for oil from them to get into the vacuum system. I would separate the vents from each other first.

 

[JMcCoy]

Both the transmission and transfer case use red transmission fluid, which does not (or should not) resemble gear oil. My bet would be a leak in the diaphram inside the CAD. They do that. I swapped mine out for a Posi Loc and ripped all the vacuum lines out. You would still have 2WL and a reliable 4wd. Then sell that vacuum BD 2WL kit. Just my .02

 

[SAndreasen]

Nv4500 uses gear oil not atf .

 

[JMcCoy]

Nv4500 uses gear oil not atf .

Good call, you are 100% correct. I missed that he had a manual.
I would still suspect the CAD.

 

[JAlford]

Thanks to all for the input. My NV4500 has a separate vent, but the NP241DHD transfer case was tee connected. But no evidence of pulling ATF into the vent line. I think I have isolated the problem to a rear seal leak on the NV4500. The gear oil was leaking onto the connection point of the plastic vacuum lines to the steel lines at the frame. I think it has softened the connectors and was sucking the fluid into the line. I was running 50% more fluid than stock, so I think the seal was flooded. I have changed the seal and lowered the fluid level, and cleaned up the crossmember. I also had to replace the transmission mount as it was swelling as well. Rubber doesn't like Amsoil, I would guess.
I pulled the lines at the actuator and there was very little evidence of oil, but the lines at the connectors had a thick film. I am assuming for the time that I have resolved the issue, but will need to check it to see what happens. I'm not sure if there is a way to get the oil out of the lines, most degreasers aren't kind to plastics.
Thanks,
Jeff