I finally got to use this for the first time yesterday. It's an awesome extractor. I used it to drain to power steering system to perform a full flush, one line at a time. All steel construction and a full selection of extracting lines make a usually messy chore a charm to perform. A few things to keep in mind, there are a lot of shut off valves on this unit. Get familiar with which valve does what. The Venturi type attachment takes a long time to build a good vacuum. I have a 14 cfm@90 psi gas powered compressor and this unit gives it a good workout to eventually get to a working vacuum.
I thought I'd try attaching a vacuum pump. I removed the Venturi and replaced it with a quarter inch fitting. I got a Robinair 15310 3 CFM pump. In just over a minute, it'll pull the tank quickly to it's operating range and well beyond into the red if you're not paying attention. I believe a 1.5 CFM would do as good a job too. I took a chance on a 3 CFM because I had no idea if it would even work, but it did.
Overall, It's a great unit. It serves as a great storage tank until you're ready to empty it.
I have a video on Youtube I made of the setup. I just can't upload it at the moment. I will try to get it on here if I can.