I call this tool, of my own design and manufacture, the Bleeder Buddy. Basically, the tool attaches to the brake fluid reservoir and then connects to a compressed air source at low pressure.  I've found a few more of my original production run in my shop and am putting them up here for sale.

By topping off the reservoir, attaching this tool and applying ~20psi of pressure, you can go to the 4 corners of the car and force the old brake fluid out. I had to come up with SOMETHING, since I didn't always have a second person around to help pump the brakes.

The tool is CNC-machined from aluminum, black anodized, and features a standard compressed air fitting. It also has the rubber gasket in the cap to seal the opening of the reservoir.

This should work on any ATE style brake fluid reservoir cap system. I've personally used this on a my 1989 Volvo 240, 1992 Audi 100, 1981 VW Rabbit, 1994 VW Golf, 1996 Golf, 1997 Jetta. I've test-fit the cap onto a number of Mercedes, BMW, Porsche, Saab, and other cars. The feedback from my customers complement the simplicity and compact size (easy to store) of the tool.