The 750017 Caroma Outlet Valve Seal is used on the new flush valves. This part will not fit the older square style valves. This is one of the leading causes for a leaking Caroma Toilet (a.k.a. a phantom flush). A leaking flush valve is characterized by an occasional refilling of the tank without the unit being flushed.
This is very simple to explain and replace.
The outlet valve seal located just before the outlet in the bottom of the tank. When one of the top flush buttons are depressed this portion lifts up. If for any reason the outlet valve seal looses it shape, (wrinkled, cracked, torn, not seated right, etc...) the water will slowly leak out around the seal and into the toilet bowl. This will eventually drop the water level in the toilet tank until it triggers the fill valve to turn on. Once the water is refilled in the tank, the cycle will continue until the outlet valve seal is replaced.
