To maintain the life of a standard pool diverter valve, you should lubricate the square seal at least twice a year. In addition you should remove the valve assembly and lubricate the 3 o-rings inside the valve at least once a year. To avoid valve maintenance you have the option of replacing these standard valves with Jandy Neverlube valves. These valves have teflon surfaces that do not need to be lubricated. This page explains what you need to do to lubricate a standard valve.