I don't know but I would think that it would need some type of hydraulic oil, maybe not. Have you sen the electric power units? No fluid at all, but pricey.
This is not within my field of expertise but what about using the hydraulic fluid in the Tranny cooling lines?
I'm not trying to steer a Mack truck.
RVS FLO is completely about outside the box thinking so I am looking for something unconventional for steering. Any body ever used a vintage screw type jack for a steering sector?
The seals in rack & pinion units don't like tranny fluid or regular oil. I don't know what makes power steering fluid different, but I've changed alot of racks because people tried to use something other than that. Tim