Last season I replaced the spider gasket and it worked great. Now, when I do a backwash/rinse and go back to filter I lose a LOT of water out the backwash line. I took the top of the valve off and the gasket was sticking up a little bit, but it looks to be in good shape. I lubed it up and put the top back on. It then filtered all night without losing water. Went to backwash again today and had the same problem. Took the top off, and gasket looks fine. Put it back on and filtering without any leaks.
The handle acts as though the spring is broken and it is hard to turn. The handle just goes up and down freely without any resistance when the top is on. When I take it off, the handle feels "normal" spring resistance but something is not right in there. There looks to be some sort of plastic ring under the handle that is broken.
The multivalve is a Pentair SM-10-3. Parts list: Parts List
I really do not want to replace the whole thing. Anyone have a similar experience and can give advice?