A couple of other reasons also that come in to play here. The wheel lift cylinders are held into the barrels with a snap ring. When they are exposed to full tractor system pressure with every raise cycle they will fail and blow out of the barrel. Also when fully raised to the bled position the angle of the wheel frame is MUCH more upright and if you happen to back up with any resistance against the tire the wheel frame WILL go over center and fail the cylinder. Then since the master cylinder controls the lowered field operating height of the main frame there would be nothing to stop the wheel cylinders in the correct position on the way down. Hope this helps.