How often should the Surestore T4 tape head be cleaned?
Never. The head has been designed to be self cleaning. Do not attempt to clean it as this is likely to damage it. Do not use solvents and cotton wool swabs to clean the head. There are third-party cleaning cassettes on the market intended for QIC drives; however they are not approved for use with the HP Surestore T4 and will probably destroy the head.