When I was out of town and the Civic's brake master went out, I bought a replacement and a few tools to do the job. Then realized I didn't have anyone to help me bleed it after install! I gravity bled the fronts for a while and left a big puddle in the hotel parking lot. Couldn't reach the rears because I didn't have a jack. Next day, met up with a guy on another forum and we jacked it up and bled all 4. There was no more air in the fronts, but obviously the rears took several bleeds to get air out.