[Cooper]

They are the three sizes of tube I used. And in the one pic I have a scribe pointing to the holes in tubes that allow oil to enter into on the downward stroke and oil to exit on the upward stroke. The smaller piston has two orings but doesn't need two. When I made it first I was using it as a guide. Well a mess up really. I just soldered bigger solid caps onto tubs, then machined the hole and inner oring grove. That way I never had to worry about messing up inner parts of tubes. Polished them before soldering/ and again after. I want to make them out of steel or stainless for project on dumper. Just don't know how easy that will be for me to work. I'm usually just brass and aluminum.