Has this job had this problem from day one? If the jacks are plumb, you might try the polishing tool from Texacone to try to get the tolerance between the piston and seal to be a little more forgiving. Have you put a micrometer on the pistons to see if there is a difference between the two pistons? You could swap heads on the twocylindersto see if there is any anomaly in the outer bore bunching the seal.
