Engine/Transmission (1998.5 - 2002) mystery vaccuum line?

[jebabb3]

i have a 99 3500 4x4 w/ nv4500+np241hd, today i found a loose vaccuum line on dr side between the block and master cylinder above the lift pump - it was not hooked up to anything. i can't find a place where this should be attached. its dark green and looks like it goes to a vent? on top of transmission. i cant find any vaccuum schematics for the diesel, does anyone know what this is?

 

[Texas Diesel]

On your truck there are three uses for vacuum, A/C & heater, cruise control, and the CAD device on your front axle.



Are any of those things not working?



Are you sure it isnt a vent line? As I recall, the 241 has a vent line that comes up behind the engine and the front axle has a vent line on the passenger side firewall.

 

[Bob V]

Sounds like the vent line for the CAD system, should have been a small breather in the end of it.