Vacuum lines and 4X4 auto adventure

[Gib]

I am new to site, but my inquires have been dealt with fast and fixed problems. Being a Ford owner for first time, you have tremendously helped me.

Doing a PM, I noticed a vacuum line on driver's side that seems to run to caliber or general area on topside. It was off and cracked. I cut line back to the good stuff, placed back on fitting and zip tied it.

I am also learning of this auto and lock on the front hubs. My auto does not work at all as in no High or Low engaging. I put hubs in lock and it works.

Does vacuum line have anything to do with this or is there another common problem in this area? Maybe it is an electronic issue?

I am trying to isolate several things. It seems when auto did work a time or two I could back into jetties, but upon departure several hours later, it seems I had lost my four wheel drive. Can truck disengage 4x4 upon start-up?

I will cease for now and wait for reply.

Thank you for your help!!

[wacko37]

I'm kinda wonderin the same thing. My auto never works though.

[maytor36]

i am also trying to make sure i understand how the "auto" 4 whl option works. I have had other 4 wheel drives that were either all manual or auto hubs with a manual shift transfer case.

my 99 powerstroke 7.3 has the auto knob on the dash. i replaced my vacuum lines from the front hubs (near calipers) and up to frame were they connect to plastic vacuum lines, just because they were old and soft. It sounds like you have a vacuum line leak somewhere, or most likely the o-rings in the front hubs themselves, but the "lock" option should overide the auto hub vacuum engagement as long as your switching on your transfer case is properly functioning all the time.

my hiccup is my hub's appear original but all i have is a "dot" on the face of the hub. i can't see any wording for lock or auto or anything. once i find the part number for a warn direct replacement for the auto hub i think i will replace the factory hubs.

[Bad Night]

Those vacuum lines are for your auto 4x4 . They are what engauges the hubs when you use the shift on the fly switch without manually locking the hubs

[Bad Night]

They way out trucks work is if you are just driving along in 2wd and hit a slick spot you just flip the switch on the dash . It engages the trans case and locks the hubs with vacuum . The reason some trucks have both this and manual locks on the hubs is because it is recommended to lock the hubs manually when you are going be in 4x4 for extended periods of time . Some examples would be plowing or offroading .