I was checking air pressure today and three of four tires seemed lower than they should have been after sitting for three weeks. Aired up and heard a leak at one valve stem. It turned out that three of the valve stem cores were loose. My BFF tire guy said it's not unusual for the cores to get loose, especially in metal valve stems. I got a Schrader valve tool and am adding snugging the cores to my preflight checklist.
Dan & Liz H
"I'd rather be happy for just one day than miserable for the rest of my life."