Kawasaki K3V pumps are a common problem with these models. The K3V pump is a high pressure, high volume pump that creates a vacuum in the water tank that feeds the toilet bowl and flushes it. The pump usually fails due to a weak internal seal that causes it to leak oil onto other parts of the system during operation. In addition, the output shaft seals can also leak causing poor performance.
The best way to diagnose a bad K3V pump is by listening for abnormal noises coming from it while it is running. Another good way is to look at the fluid level inside your water tank after you flush your toilet. If it does not drop in about 10 seconds then you most likely have a bad pump that needs replacement.
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