What’s this part called (freightliner cascading 125)

Probably a transmission cooler line
But could be something more unique as others have suggested

 

Put your finger on it and lick your finger. What does it taste like? Or chase down the line.

 

I see 2 compression fittings, a 45° elbow, a radiused metal line and a bracket. Oh, and a bit of light leakage.....