Clean and polish the pastic parts too. I you can give the moving joints a drop of oil and smear grease on parts that creak. I cleaned the conductor parts and left them as clean and tracefree of any substance as possible. I have yet to open the cartridge containing the carbon disks. For a while I thought mine were sealed, but it's only a putty like thing you can scrape off. I have a knee controller on a 99 I need to sort out.