Check them and replace as needed. hold the lifter in your hand and press the roller toward the top of the lifter,then take a very small screwdriver or pocket knife blade and insert it between the lifter body and roller. while holding upward pressure with one hand pry the roller away from the lifter body. if there is more than .003/.005 movement replace the lifter. if when you roll the roller around with your finger there is any roughness to it replace it. if they check good run them for another cycle.Bill