Turned out that the large gray boot/gasket had finally started to harden and deteriorate right at the bottom where the drain hose is. No surprise it leaked after seeing that. Installing the new gasket (and new clamps which I figured I would replace at the same time) did the trick. Fairly simple install. Do yourself a favor and buy the spring pliers to remove/install the clamps. Well worth the time and hassle they will save you.