The seal to the sink is good. The waste pipe connection is dry. It is not rusty. If the sinkerator runs with a small water flow, there is no leak. If there is a large water flow, it leaks from the metal base of the unit where the pipe to the switch etc connects. The leak is either through or round the motor.I suspect that there is a faulty seal where the motor shaft enters the grinding chamber.
I am quite good at mechanisms and have little doubt that I could dismantle the unit, which has now been uninstalled. Would I be able to get necessary spares?
The local service agent does not answer his phone.
In spite of your doubts I have successfully dismantled my insinkerator and confirmed that the fault is a rust hole in the grinder chamber base plate.
The only real cure is a new plate, but I cannot find a source of spares. Do you know of one?
Additionally, I have been unable to undo the bolt holding the grinder plate on to the motor shaft. I have used a hex-key to hold the shaft and a quality socket wrench to turn the bolt. I bent the hex-key. Is the nut left handed? (although I have tried that without success) Do I just need more force?
Have you dismantled an insinkerator yourself?