Tire Valve Core
A spring-loaded metal valve pin inside the tire valve stem that regulates the flow of air into and out of the tire.
The tire valve core is the small, spring-loaded mechanical component screwed into the center of the tire valve stem. It is the gatekeeper of tire pressure, allowing air to be pumped into the tire when depressed, and automatically sealing the air inside when released. The valve core has a small rubber seal that presses against the inside of the valve stem to prevent air from escaping.
Over time, the rubber seal on the valve core can degrade, dry rot, or become contaminated with dirt or moisture, leading to a slow air leak. A leaking valve core can be diagnosed by spraying soapy water onto the tip of the valve stem; if bubbles form, the core is leaking.
Replacing a valve core is a quick and inexpensive process that involves using a valve core tool to unscrew the old core and screw in a new one, followed by refilling the tire to the correct pressure.