Identify this piece??

[MtnVol]

Hello everyone, I have a 1997 Chevy Tahoe and while sitting over the past few weeks all of the water in my radiator seems to leak out (even when not running). I noticed water is steady dripping from the small piece that is in the photo. Not sure if this is the main problem or not but water is definitely coming from this piece. It is on the left side rear of the engine.

 

[Nurser]

I believe it is called the "heater control valve". Mine was leaking too. I replaced it last month. $20 part from Advance Auto. Needed two pair of pliers, one for clamps, one to twist hoses, and 30 minutes. Simple fix. The old valve was very brittle inside of the hoses. This is where it was leaking. Be careful not to let the broken pieces flush downstream. Good luck.
Top off coolant at the end.