Flat towing 1997 f150 4x4

I can't tell you what vacuum line is meant but it's not for the front hubs. There are no hubs. IFS front on those.

May be the actuator for the front differential.

I believe the hubs are vacuum operated. I just don't get with the engine off why the need to cap a vacuum line. Also if I do need to cap one of the vacuum lines which one (what color). Has anyone on the form towed a 1997-2003 f150 auto trans manual transfer case please let me know what the deal is. Thanks Robbie

Are the front hubs manual or auto? Its easiest and safest imho to simply remove the rear driveshaft if traveling a long distance. If the driveshaft is not removed than yes, trans in park and TC in neutral will be just fine

Im assuming the hubs are auto vacuum operated... Not sure why you would need to cap them. If theyre a concerned simply unplugging them should be fine. Interested to hear what others say about them