I have a Kohler K-597-VS faucet on my sink and the handle leaks when closed. No obvious leak when water is running. What is the likely failure (o-ring?) and how do I take it apart to get to the problem?

Turned water off and removed the handle using an allen key and then unscrewed the plastic cap. The threaded ring holding the valve in place was not tight. Easy fix.

Turned water off and removed the handle using an allen key and then unscrewed the plastic cap. The threaded ring holding the valve in place was not tight. Easy fix.

Here is exploded view of your faucet. Make sure #1 is tightened. It is a large, brass, nut. If still leaks, replace #4.

Hope that helps

Milo