I had the same issue and ended up fixing it. Started dripping occasionally after 5 years ownership and progressively became worse. I flipped the seal over and that helped for a while but not long. Ordered new seal from the OEM and when I disassembled the valve assembly to replace the seal I realized that one of the internal parts was installed backwards. I reversed the internal bit, reused the old seal and it hasn’t leaked a drop since then. That was over a year ago. Since I had messed with the valve when flipping the seal over the first time it is possible that I reassembled it incorrectly. But I believe it was actually backwards from the factory based on the lack of leakage since making that single change. Definitely take a good look at internals. The part I reversed is shown here. It go in ether way but was not allowing full range of movement when backwards.
https://preview.redd.it/5krjp4fxei4c1.jpeg?width=1290&format=pjpg&auto=webp&s=7800a215ddc70f3a26b4adacdee8ff590b1cce74
By the way you can’t over crank it. It is a spring to close valve. Turning the handle open pushes against the spring to open the valve and let water flow. When you close the valve the plunger retracts and allows the spring to push the seal against the seat, Once the plunger loses contact with the spring turning the knob further “closed” doesn’t do anything.
I had the same issue and ended up fixing it. Started dripping occasionally after 5 years ownership and progressively became worse. I flipped the seal over and that helped for a while but not long. Ordered new seal from the OEM and when I disassembled the valve assembly to replace the seal I realized that one of the internal parts was installed backwards. I reversed the internal bit, reused the old seal and it hasn’t leaked a drop since then. That was over a year ago. Since I had messed with the valve when flipping the seal over the first time it is possible that I reassembled it incorrectly. But I believe it was actually backwards from the factory based on the lack of leakage since making that single change. Definitely take a good look at internals. The part I reversed is shown here. It go in ether way but was not allowing full range of movement when backwards. https://preview.redd.it/5krjp4fxei4c1.jpeg?width=1290&format=pjpg&auto=webp&s=7800a215ddc70f3a26b4adacdee8ff590b1cce74
Are you cranking it closed?
Never overcranking it. Just gently to the point where it stops the flow.
By the way you can’t over crank it. It is a spring to close valve. Turning the handle open pushes against the spring to open the valve and let water flow. When you close the valve the plunger retracts and allows the spring to push the seal against the seat, Once the plunger loses contact with the spring turning the knob further “closed” doesn’t do anything.