Ross, yours is due for a rebuild...
Should be done every 5-6 years. It's not at all unusual for a PH II to keep working for years and years without any obvious problems, but as seals and o-rings become more and more worn, the pump gradually becomes less and less efficient...so gradually that you won't notice it till something in it finally fails. But after 9 years, you should notice a distinct improvement after a rebuild. You should also lube it every spring with thick teflon grease...that'll do things: extend the life the pump and keep it pumping smooth as glass. Even without ANY maintenance, a PH II should last at least 15 years...maintain it, and it'll last up to 25 years.
