1992 Ford Aerostar

Engine Performance problem
1992 Ford Aerostar 6 cyl Two Wheel Drive Automatic 150000 miles

The part I need to identify is located on the underside of the vehicle on the driver's side. It appears to have an intake and outgoing port that connects to what look like hydraulic lines, although in the attached picture one of the ports is broken off. I also appears to have a vacuum line that attaches to the top or the large round part. When it broke, it appeared that some type of oil came out and the vehicle filled with smoke. I have attached a picture of the part. What the heck is it?

November 12, 2009.

Was it coolant that came out? Do you have rear heat / AC? It almost looks like a heater control valve.