questions: is this what I think it is, and how important is it?

 

thanks to all who helped me with the last issues, now I found the real culprit as to where coolant was leaking.  apparently the little plastic piece is called a Termocontrol valve assembly (described it to a shop and that's the answer I got).  it is a little plastic elbow with some kind of valve in it, has ~13mm bolt on the end of it. not sure how one would turn the bolt, as the plastic it is threaded into is crap.  it might be heat activated. the valve is connecting on both ends by 1/4"ID hose.

 

location of this piece: from the water pump, there is a rubber elbow hose about 6" long that connects to a metal T under the air filter (not in it), and behind the alternator. the top of the T connects to heater hose that goes through the firewall. the stick part of the T  has a 1"piece of what looks like 1/4"ID hose connecting to the plastic piece I described above. following that plastic elbow, the next piece of hose connects to the base of the hitachi carb.

 

so, I am in there, now I don't exactly know where to go from here. my instinct tells me to skip it and just leave it out of the picture. my instinct also tells me I am an idiot and will probably screw something up and should as a professional. thanks again USMB

That piece is a seperate thermostat that controls heat to the carb base.

Most people don`t know it exists.

 

I think you could safely eliminate it for the winter at least.(replace it w/an elbow)

Might make the manifod too warm in summer though.

You could block that line in summer if necessary.

 

Looks to be a discontinued part.41720 7010

 

I do not think you need to turn the "bolt".

ahhhh. thanks for the advice! it does look thermostat like from what I can see through a 3mm hole.

If a replacement is needed, you might be able to find one on a similar subaru at a junkyard somewhere.