Radiator Replacement and small lower radiator hose mystery

[Nobleprofessor]

I am going to be replacing the radiator on my 99 740iL. When I removed the radiator from my donor 2000 740iL, I found something I didn't know I had. On the bottom of the radiator on the driver's side is a small hose. I thought the only hoses were the upper hose (that goes to thermostat) and the lower radiator hose. After I removed everything I realized that small hose was still connected. Most of the pics I have reviewed on here and on e38.org, don't show this hose? It is a coolant hose, but I don't know what it does AND I don't know how to remove it. Anybody know? or have some tips.

[motion]

I believe you're talking about the transmission heat exchanger line. It's a short hose with a preformed bend in it, if so turn the fitting at the bottom of the radiator 90degrees and pull down. There may be some residual coolant that may come out. Consider changing all of the hoses while at it. Also consider installing two Fumoto valves (F106N) in your block drains. As always do as you feel is best.

[carnut1947]

Are you referring to the small hose that circulates coolant around the alternator?