2 holes go up to the heads. 1 on each side. You will know when the holes are in line. It will only do one hole at a time. When they are not inline, the drill will try to twist your hand off, when inline, the oil will fill up in the head so quick, you will be wiping the floor. It only takes a few seconds per side to get them purged. So keep twistin on the crank with the drill going, you will find the sweet spots.
