I had a horrible leak in my Wagner lower helm on my new boat. A zinc piece had disintegrated into crumbs allowing oil to squirt out. After looking at everything I could find on the web about the scarcity of Wagner parts and no agreement on which specific hydraulic oil(s) work with my old model, I went to the hardware store and bought new o-rings and Brand X hydraulic fluid.
The fluid, which I also use for my log splitter and garage jack was $14 for a gallon. No dye or anything. So far, when I turn the wheel the rudder moves due to hydraulic pressure. That was my goal. Time will tell if I have a catastrophic failure for not using the right colored expensive stuff from a marine store, assuming people can finally agree on which is the right one. Color me sceptical.
Mark