Same here. A lot of the fluid has leaked out the 2-3 times it’s been moved and leaned sideways because someone didn’t know to not do that. I’ve been told to use 5W30 motor oil. Also, type F transmission fluid. And then not to use hydraulic fluid at all. I found a blurry photo of a faded tag that said the new chair came with a bottle of oil and to never use linseed oil in it. It said to use a funnel to pour some under the seat. Pour in a little, pump the lever, and when it raises you’re done. Don’t add more.
I need to know exactly what to use before I screw it up. Thanks in advance.