Since I'm new here I thought I should try and help, SK-6015 Piston Seal Rebuild Kit (Includes Piston Seals, Energizer O-ring, Wear Bands) is what you want. Be especially careful to mark how everything goes together (take pics, mark tubes that connect together, note the direction of the tab on the cylinder heads go so in and out go the right direction), and be especially careful of the copper tubes that connect it all together. Don't kink them. Test before you hook back up to your system. If you don't know what you are doing or are the least bit hesitant, send the machine out for service. PLEASE. You will need a torque wrench, screwdriver, wrenches, vacuum oil, razor knife, and some threadlock. I would recommend a camera, permanent marker, and a bowl for screws and bolts. Please be gentle in your criticism of my post, I'm new here. Hope I have helped.