[LazyPup]

The leak is present even when the water from the faucet is caught in a pan, therefore we can rule out the drain system as the source of the problem.

The faucet inlet pipes extend through the sink and the supply lines are connected about an inch or two below the sink therefore if the leak was originating from a supply tube the water would be running down the supply tube and dripping off the angle stop.

The clevis is attached to the lower end of the drain stop lift rod, which is extended down through the faucet set, which means the leak must be originating from the faucet set above the sink.

I would suspect that one of the faucet stems has loosened up and the water is leaking where the faucet stem meets the faucet mixer body. The water is then traveling by surface tension until it reaches the low point on the faucet body and is transferred to the lift rod, where it passes through the sink opening and on down the lift rod to the clevis.

I would suggest you remove the faucet handles and tighten the faucet stems. If that does not solve the problem you may need to replace the fiber gasket between the faucet stem and the mixer body. (replacement gaskets can be found at any local hardware store, but you will need to turn the water off at the angle stop and remove a faucet stem, then take the stem with you to the hardware store to be sure you get the correct gasket.)