A tire valve stem is the small pin sticking out of the tire that holds air and lets you inflate or deflate the tire as needed. As small as it might be, the tire valve stem plays a big role in ensuring your vehicle’s proper operation.
The tire valve, also known as the Schrader valve, was invented by August Schrader in 1844 for the Goodyear Brothers. Schrader valves are considered universal valves that can also be found on motorcycles and trucks.
Other variants, such as the Presta and Dunlop valves, are mostly found on bicycle tubes instead of motorized vehicles.
Compared to the Presta and Dunlop valves, the Schrader valve is the largest and the most common type to be used in compressed gas and pressurized liquid applications.
Aside from tires, the valve stem is also used in various systems, such as fuel injection, air conditioning, and air shock systems.
A typical tire valve stem consists of a core, cap, and body.
The valve core sits between the cap and body. It serves as the inner sealing portion of the valve stem and prevents air from escaping the tire.
The valve cap prevents moisture and debris from contaminating the valve core. It can either be plastic or metal with a knurled or hexagon design.
The valve body is the component that houses the valve core. It comes with standard threads where the cap is screwed on.
There are generally three types of valve stems一rubber, high-pressure, and high-performance.
The rubber valve stem is commonly used in passenger vehicles that require a tire pressure of 65 PSI or below.
The size for this type usually ranges anywhere between 0.7” to 2.5”. Rubber valve stems usually fit rim holes with a diameter of 0.453” or 0.625”.
Some rubber valve stems sport a chrome sleeve and valve cap to give tires a more enhanced look, but these variants generally have the same specifications as the standard rubber tire valve.
High-pressure valve stems are designed for medium to heavy-duty trucks and trailers with steel wheels.
This type is for vehicles that require a maximum cold inflation pressure of 80 to 100 PSI.
The size of high-pressure valve stems can range from 1.25” to 2.0”. Similar to the rubber valve stem, this type comes in two rim hole fittings一0.453” and 0.625”.
High-performance valve stems are designed for race cars and vehicles that are driven at over 130 mph. This valve stem can hold a maximum cold inflation pressure of 200 PSI.
High-performance valve stems usually have a standard diameter of 0.453” and 0.625”, but they also come in rim hole fittings of 0.236” and 0.315”.
Unlike the two valve stems, this comes in two fitting types. High-performance valve stems can have their retaining or holding nut inside or outside the tire’s rim.
Some valve stems are connected to a tire pressure monitoring sensor, which alerts the engine computer whenever one of the tires is underinflated.
The TPMS is an indirect system that relies on the information gathered by wheel speed sensors.
This system monitors the rotating speed of diagonal tires and checks whether or not one of the tires is producing a smaller rolling radius than the other.
The TPMS adds the speed of diagonal tires and subtracts that value from the other set of tires. If the difference is less than or equal to a threshold value, the system won’t send a signal to the powertrain control module (PCM).
But if the difference in inflation pressure is 12 PSI or more, the PCM will activate the low tire pressure warning lamp to alert the driver that one of the tires is underinflated.
Experts recommend replacing the tire valve stem every time you get a new set of tires.
Although you can replace a valve stem without removing the tire, the stem’s rubber components can dry out and crack, which can lead to air leaks or total air loss.
A tire valve stem replacement can cost around $10 and is generally considered an easy task. But if you’re thinking about bringing your vehicle to an auto repair shop to get the job done, you might need to shell out a couple more bucks.
Before you replace a tire valve stem, make sure that it’s the part that’s causing a leak and not the tire itself.
One way to check if the valve stem is leaking is by combining water and dish soap and pouring the mixture over the uncapped valve stem.
Bubbles forming at the end of the stem indicate a damaged tire valve.
In most cases, wear and tear could have damaged the spring-mounted mechanism inside the valve core.
Proper tire maintenance can also mean a long service life for valve stems. Here are some tips you might want to look at to get the most out of your tires.
Rotating the front and rear tires is one of the ways to extend their service life because it can even out tread wear. Experts recommend rotating your tires once every 10,000 to 12,000 km or every six months.
Your tires should have the right amount of pressure. Over or underinflated tires can result in acceleration, braking, and steering problems.
Getting your wheels aligned once every 25,000 km prevents uneven tread wear.
Check your tires for any signs of cracks, bulges, punctures, and uneven tread wear.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.