under dash question?

[Blair Mahaffey]

I pulled out my glove box and under dash panel on the passenger side in order to replace the tube running from the thermostat sensor to the other side. (The middle section had disintegrated and Larry Bible had posted about how to fix this problem. Thanks, Larry).

Anyway, under the dash panel is a large compressor type object with tubes running to it. One of the tubes is leaking. What is this piece of machinery and do I need to have it checked?

Blair