I would think you could clean it with diesel fuel or kerosene, and I use AW 32 hydraulic oil, some folks use a multi viscosity oil like this https://www.oreillyauto.com/detail/o-reilly-oil-4527/chemicals—fluids-16461/grease—lube-16582/hydraulic-fluid-17707/o-reilly-oil-5-gallon-hydraulic-fluid/80024/4601129
Our mechanics use brake clean to clean the intank filter as it evaporates quickly and removes all tarnish. We also find that the hydraulic systems seem to work best when using HW46 hyd fluid or AW46.
Tyler Nystrom
Keno Tractors
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