[OldFoggey]

AKA, you were right on about the 10m x 1.50. I bought a cap screw at Home Depot but they didn't have the rubber washer that I could find. I found that at Tractor Supply. The screw was treaded all the way to the head so I didn't use an o-ring figuring that the threads would cut it anyway. Seems to have cured the coolant drip.

Thanks...Don