Volkswagen: brakes have no pressure, vw passat, pressure bleeder

Question
i just changed the bake brakes on a 2003 VW Passat and now i don't have any pressure on the pedal with the car running. when the car is off it is fine but when running it goes straight to the floor. i did have to remove a brake line to get to one of the bolts to get the caliper off so i think that maybe i got air in the lines like an idiot. at least i hope that is all that it is. so i guess my question is do i bleed the brakes or take it a mechanic? please help.
thanks
Jeff

Answer
If you opened a line, it needs to be bled.  It's better to use a pressure bleeder, but it can be done the old fashioned way too.  Get a small jar and a length of tubing that will fit on the bleeder nipple.  Get an assistant to push the brake pedal.  While your assistant presses the pedal, open the bleeder a bit.  Before they release the pedal, close the bleeder.  It's best to do this when they are at the end of the downstroke.  When the fluid is clean and bubble free, that caliper is done.  Make sure the reservoir stays full or you will need to start over.  You will need to do all calipers starting from the one furthest from the master cylinder working to the closest.  Make sure your assistant is sober and paying attention to your instructions.

BTW- If the fluid has been in the car for two years, it should be completely replaced anyway.  Buy a fluid that is a different color from the original and it will be easier to tell when all the old fluid is out.