Understanding Valve Stems
So what is a valve stem, and why is it so important? Valve stems are a basic feature of wheels and play a critical role in tire and wheel safety. They are necessary to keep your tires inflated and allow you to add or remove air as needed.
How Does a Valve Stem Work?
Valve stems are made up of a body, core, and a cap. The valve core is the inner sealing portion of the valve stem that prevents air loss. The valve core should be tightened into the valve body for a proper seal.
While the valve cap helps prevent air loss with a rubber seal inside the cap, it’s main function is to keep dirt and debris from getting into the stem and contaminating or corroding the valve core. If moisture gets inside the valve stem and freezes, it can cause air loss and/or a flat tire.
The rubber components of valve stems can dry out and crack over time, causing air leaks or total air loss. To avoid this, we recommend replacing your valve stems at least every time you replace your tires.
Types of Valve Stems
Standard Rubber Valve Stem
These valve stems can be operated at air pressures of 65psi or below and are typically used on most passenger vehicles.
Chrome-Sleeve Rubber Valve Stem
These valve stems can also be operated at air pressures of 65psi or below and are very similar to a standard rubber valve stem, but they have a chrome sleeve over the valve portion for enhanced appearance, as well as a chrome valve cap.
High-Pressure Valve Stem
These valve stems are used on light trucks and trailers when the air pressure requirements exceed 65psi.
High-Performance Metal Valve Stem
These valve stems are recommended for high-performance purposes. Because a rubber grommet is used to seal the metal performance valve to the wheel, they will still require replacement over time.
They are attached to the wheel with a nut and rubber grommet. The nut can loosen over time and must be tightened periodically to prevent air loss.
Tire Pressure Monitoring System (TPMS)
Most vehicles after the year 2007 come equipped with Tire Pressure Monitoring Systems (TPMS), which monitor your tire air pressure. While most TPMS sensors also use valve stems to add/remove air, the valve stem portion of the TPMS sensor is different from a standard valve stem.
Learn more about TPMS Sensors and Rebuild Kits