Odd G-Max Fill Valve behavior

My power was just restored after a week of darkness following Hurricane Ike. Since I'm on a well, i've been flushing my Toto Vespa by pouring a bucket of water into the tank. Now that the well is working again, the toilet flushes normally but there is about a 5 second delay before you hear the tank begin to fill. Prior to the outage, the tank was filling immediately after the flush. It seems to work normally other than that, but the delay is kind of strange. There is some alge growing in the tank and some pieces are floating around, but it was doing that before the outage.

Any suggestions?

Dave

valve

The rubber diaphragm in the valve may have hardened while it was without water, and so it takes that few seconds to flex enough to open and let the water flow.

Lowes has the replacement assmebly cap for $2.47 mady by Korky.
https://terrylove.com/korky/