Originally I put new rings on the lift piston and it didn"t really help. They were genuine Massey steel rings. Just out of curiosity I had the piston laying there and I took the rings off and measured them. The new ones I had measured exactly the same as the wore out ones that came in the tractor in 1951! I new the cylinder was in spec so I put one of the new ones in and sure enough you could put a .010 feeler gauge in between the ends...which according to the manual you are supposed to discard them if you can do that. I had 2 other old sets out of a TO30 and an 8n and both were thicker than my new ones. So I guess if anybody else buys new Massey rings you better measure them first. It doesn"t matter cause I resolved it with the hybrid piston set up. Two steel rings and the NAA oring and back up washer installed where the 3rd ring used to be....problem solved.But I thought I would share my findings.