Antifreeze Leak

[Eastbx]

Gentlemen, I've been noticing a small leak of antifreeze coming from a valve on the right side of my 2004 TC40A. I don't know what this valve does, what's it called or if this is normal...? I'll attach a couple of pictures for more details. Maybe someone can give me some advise or direction on how to fix this relatively small problem? It would be greatly appreciated.
A little more detail on this leak, it looks like it's coming from the threads rather than the nipple. Can I take it off and put some Teflon tape and reinstall it. Should it be replaced all together?

 

[Soundguy]

I see this post title in a couple places.

Is it the block drain, rad drain or a bypass hose, easy enough to check, my nh 1920 was on that side.

 

[Ford850]

Looks like a draincock.
Messicks Part Search

 

[ruffdog]

Here is a thread (tc33d) that is about the same leak location with pictures.

http://www.tractorbynet.com/forums/new-holland-owning-operating/323012-coolant-leak-question-tc33d.html#post3909938