^you dont need to suck out all the old fluid from the reservior.
the proper way to do it w/o a vac is pump ur brakes to build pressure, then open the bleeder valve a bit (holding pressure on the brake pedel depressing it all the way. once it is depressed all the way, you can CLOSE the bleeder valve and pump the brake a few more times to build pressure and do it all over again...
ORRRRRRRR
go buy some "speed bleeders"
they replace ur old bleeder valves, but the cool thing about them is that they only allow brake fluid to flow out when they are open. so they wont let air back in.
i can FLUSH my entire civic's brake fluid system within 5 mins w/o any air bubbles in the lines.
here is a better image of them for you guys to get an idea:
