Well I did the water-soluble test and yes it was. Pulled the circlip and spent 5 minutes looking for whatever flew out. Boy is that thing under a bit of spring pressure. I am hoping it just consists of one spring, one piston and one circlip. Please say it is so? The unit once wiped clean is in perfect condition so I am glad I decided to pull it and check it out before rust started. All surfaces are smooth. bearing feels fine so I will grease and put back together. Thanks for your help, again.