Well, I guess if it goes flat again I could take it back to the service station and tell them about this. Thanks.
Also very helpful information to keep in mind. Thanks.
Valve Stems Can Often Be Checked Right On The Vehicle. Spray A Goodly Dose Of Cleaner Product, Such As “Fantastic” Or Even Window Cleaner At The Valve Stem.
Then while carefully watching and listening, wiggle the valve stem about. Continuously forming bubbles or telltale " . . . s-s-s-s-s . . ." are what you’re looking for.
You may want to do this near a tire repair facililty. I learned this little trick while checking a leaky garden tractor tire. When I wiggled the suspect valve stem, it broke right off in my hand and all the air escaped ! It was the leak problem and was so rotten that it literally fell apart. Luck for me, I could install my own stem on that wheel.
Always pay for and receive new valve stems with new tires. Be careful, though. Most cars of recent model-years have expensive TPMS stems (Tire Pressure Monitoring System). Each wheel transmits its pressure reading to a dashboard display in the car. Always ask about that before having somebody tear the stems off. I believe some have seperate stems and transmitters, which helps.
CSA