swimming pool sand filter repair

[John Keiser]

I have a 20+ year old Tahitian sand filter which has worked reliably. The valve's "web" gasket has begun to leak [I get an extremely slight leakage on the backwash side] but, as far as I can tell, is no longer available for replacement. As a result of the leakage, the system no longer holds a vacuum overnight and pumps air for a few minutes every morning. I am now getting an occassional small amount of sand injected in the pool just after startup, and usually some with the backwash if I haven't been running the pool first. There are replacement laterals available but I'm thinking that the sand may be caused by cavitation when all the air is pumped at startup. I hestitate to spend the time checking out the laterals if cavitation is the cause due to the web gasket. Am I on the right track? Any suggestions on fixing the web gasket? Thank you.

[buffalobill]

try:

[John Keiser]

Good source but not much joy as the site says the valve parts are obsolete and suggests a complete replacement valve for $182.00. I almost wouldn't mind the price if I were a bit more confident that the sand discharge is caused by the worn valve gasket as opposed to a cracked [and possibly irreplaceable] lateral. I shall ponder some more.