If its the hydraulic motor I got a guy who rebuilds them for cheap. He went through one on a 1990 qt15N we have. He said a bearing that collows a cam goes out over time and Mazak likes to sell the whole unit instead of the bearing..unless you know the part #.
Thank you for trying to help,but my problem is in the piston itself.The motor was rebuilt,but something is leaking inside thus cousing high heat emision,and the machine can't run more then 2 hrs. I would need a new piston or to rework it and make it right.If this guy knows what I am talking about,please let me know.