A tire inflation apparatus for inflating a tire mounted on a rim comprises an inflation head mounted to a moveable inflation shaft of a head position cylinder and an assist cylinder mounted to a frame member, with the frame member and assist cylinder positioned above the inflation location. The assist cylinder includes a moveable assist shaft operatively connected to the inflation shaft by a moveable cross member whereby the head position cylinder and assist cylinder cooperatively operate to selectively position the inflation head. The inflation head is positioned in a retracted position by vertical upward extension of the assist shaft and positioned in a tire engaging position by vertical downward retraction of the assist shaft. A fluid passage in the inflation shaft may deliver pressurized gas into a tire inflation cavity of the inflation head for inflating a tire when the inflation head is sealed against the tire.