Back when i was a kid 1972 on the farm we used 20wt non detergent motor oil on all filters small. And when they started selling the same thing for 10X more with a little color it was pure geinous. 15-40 like for diesels is all non detergent unless they say other wise on the bottle And as far as using WD-40 for cleaning? I woulden't use it if it were the last thing.I'ts a pennetrant, and it premotes rust and has noLubricating factors whatsoever It should only be used to loosen rusted Nutts. And as for plastic and electrical it weakens it, and is conductive to electricity and can explode. I know all these for fact, cause on the farm, you get boared, and experiment, and observe.
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