I am in the process of cleaning up some parts and am wondering if I can soak the entire idler arm assembly in evaporust?
I would remove the bushing first, with the intent on replacing it, then do the Evaporust steps.
Read the warning on the jug - you got a week or two before rust sets in.
The same question for the fan clutch. I worry about soaking moving parts in evaporust.
Any liquid, Evaporust included, will get into a moving assembly. The instructions include a rinse in water after an Evaporust treatment. As far as I'm concerned, that is a recipe for more rust. What I've considered, but haven't tried, is to use brake cleaner to blast out any remaining water on a moving assembly. I would not use a spray oil (Wd-40) unless you are at the final step, aka done (no paint, no plating, etc).