So now why all of a sudden would I be getting rub marks on my cooler line? It's not being touched when stationary, but what would even be the reason for this change to allow the cooler line to be touched when in motion anyways?

 

With an inspection mirror, are those threads nearby also bright? While you work thru this, how about a split piece of heater hose and two clamps to cut down on the physical contact?

 

any front end vibrations? have you had any hard shunts? check your torsion bar and bushings as well as any mounting hardware and bolts.

 

That would be a massive amount of vibration for those bolt threads to touch. Could you have caught something on the road? A C-130 doesn't even vibrate enough to make that far of a stretch

 

I had just replaced those on mine, and it is hard for me to figure out from the picture, but depending on which one, there are a few spots where the line uses brackets to stay in place. If you follow the line, any chance a bracket might have come off and it is the pipe the is not secure? The ones I remember are a simple single bolt with two plates that sandwich together.

 

it looks like you sway bar is flexing into the line , probably a worn bushings on the sway bay or the lower control arm mount...