gravity bleeding is what you do before bleeding the calipers on abs. its where you open all 4 of the little bleeders at once and fill the res, leave the cap off, and keep refilling as it pushes fluid through and air bubbles out the top. then you go through and close all calipers and start with farthest from the mc, and work your way around doing the pump and bleed method individually. they are absolutely wonderful now!