You step out into the driveway ready to start your morning commute only to discover a flat tire. How in the heck did that happen overnight? If the tire valve is missing its cap, the culprit might be a leaky valve. Those little caps keep out dirt and moisture that can cause leaks,
so be sure to keep caps on all your tire valves.
When you replace tires, remind the tire shop that you expect new valves with the tires.