Just finished replacing new pads all around, and new rear rotors and rebuilt calipers. I've bled twice, but still have a little sponginess going on. Never had this problem before. Do I need to bleed a third time, and flush out any trapped air, or what the heck? How many times do you guys open and close each bleeder fitting before moving to the next one? I only opened up the rear lines for the new calipers this particular brake job, but didn't bleed them till the following morning. I noticed that the new calipers were already full w/ fluid that siphoned back(just a minor bit of air) when I bled them. I also read that air can get trapped in the anti-lock brake system hydraulic control unit. And if this happens, your suppose to bring it to dealer or someone who is capable of bleeding with the aid of a scan tool? What?