I changed the kitchen sink faucet. I followed all directions and everything looks fine. No water leaks from the faucet or from the connection between the faucet water lines and the water lines that goes into the stop valve.

However, I noticed that when I first closed the stop valves to cut off the water, water started to leak from the valve as I was closing it.

After changing the faucet, I turned the water on and noticed that water leaked again from the valve. And it has not stopped leaking. It leaks about one drop per minute.

How can I stop the leaks without changing the stop valve??? HELP!!!