I bought the german auto products power bleeder that you hook to the resovoir and pump up so all you must do is open the bleeder screws at the wheels and wait until it runs clean. I usually change brake fluid with every set of pads, and its never that dirty. I only use Castrol GT-LMA dot-4 brake fluid.

__________________
Matt
2003 Jetta Wagon TDI 145,000MI
1999.5 Jetta TDI 287,000MI
2001 Suzuki SV650S 26,000MI
2008 Yamaha Vino 125 11,000MI
http://www.crazymatt.org