Step 10: Clean the bottle jack unit's passageways
Inspect the seats in the bottle jack unit's body for signs of rust and pitting. The seats need to be clean and smooth. When I let sunlight shine into the recesses where there are seats, I saw more dirt. I used a wooden dowel rod to scrape and break loose any dirt I could find. I poured some jack oil into the holes to flush the dirt away.
Second photo--Clean the groove that receives the tank's outer shell. It has some brown dried oil residue. Something brass would be ideal. It would be tough enough to remove the residue, but would not scratch the machined surface. Someone said jack oil is a vegetable oil. The oil residue is certainly like what I have seen in the kitchen from vegetable oils.