I have 3 hoses total running from the inside of my cab and out the fire wall. 2 hoses lead to the front differental while the third leads to the back of the intake manifold. Really curious on why the previous owner would do this or even what they do, any thoughts?



In the pic below, towards the back of the manifold. You'll see 3 hoses, the one running from the cab is the top most one.


2 Hoses on the front and side of the front differential.

 

Its so you can lock/unlock the ADD actuator at will. You can use "2wd low" while retaining the ADD system.

 

It all makes sense now! haha. Thank you. On a side note, the truck has manual hubs. So the whole air hose system is pretty pointless, but none the less at least I know what it does now.

 

No, Its still useful, Its Nice to have the hubs locked on the trail and use 2L and not have the binding or steeringwheels pulling back and and forth.

Up to you.