H.K. Sawyer of Northwest, Ga., submits this advice: “You say you’re tired of that nastiness that builds up on your oleo struts? And, in general, down there?
You can, and should clean it, regularly. BUT don’t wipe your landing gear oleo struts down with any sprays or lubes other than hydraulic fluid. I am told that various ingredients of many oil spray products will attack the hydraulic seals. That will hasten their failure slowly.
Keep a can of the recommended hydraulic fluid handy and wipe them frequently.
Don’t grind sandy particles onto the shaft or embed them into the recesses.
Don’t spray your landing gear with degreaser to make it shine because the degreaser will find its way into the internals and degrease them as well.
If you already did, then don’t sweat — just make sure you have a good cleaning and lube performed, preferably alongside your favorite mechanic, and you will know how to do it next time. Give him something extra for allowing you to be there, and learning from his knowledge. It’s worth it. Besides, his time is valuable.
Degunking areas where dirt and particles become embedded is a good practice. Don’t be afraid to get your hands a wee bit dirty! You can always use medical type gloves also.
While you’re down there getting nice and grimy, check your tire pressures and inspect them carefully.
You can use the same logic in cleaning around the brakes. Believe it or not, strong soap and water and a toothbrush works pretty darn good!
But the lesson is not to use solvents or degreasers just to make things pretty when you don’t know what the contents will do.
Source: http://generalaviationnews.comTip: How to properly clean oleo struts