We recently encountered a customer who faced an expensive repair due to installing aluminum metal tire valve caps on their vehicle’s wheels.
When temperatures plummeted below freezing, their vehicle’s tire pressure monitoring system (TPMS) alerted them to a drop in tire pressure. The customer’s next step was to increase the tire pressure. However, this is where the trouble began.
They found themselves unable to remove the metal valve caps from any of their tires. The caps were firmly seized to the valve stems, seemingly corroded in place. Despite their best efforts, they couldn’t loosen them.

At local tire shop Castle Tire, a technician also failed to remove the stubborn caps. The unfortunate news: the metal caps were corroded onto the valve stems, necessitating the replacement of all four tire valves and TPMS sensors – a substantial expense.
The technician explained that this issue stemmed from a chemical reaction between the dissimilar metals. This is particularly common in areas with salty roads or high humidity. Corrosion can occur rapidly, especially with aluminum TPMS stems. In some cases the tip of the TPMS sensor can snap off (see image).

The inexpensive plastic caps provided with your vehicle are designed to prevent this type of corrosion. They are durable, weather-resistant, and won’t corrode and seize to the valve stem.
While metal tire valve caps might seem like a minor upgrade, they can lead to significant and unexpected repair costs. To avoid costly repairs and maintain proper tire inflation, stick with the reliable plastic caps that came with your vehicle. If you find yourself in the situation where you’re unable to remove metal caps from your wheels, Openbay can help you find a qualified tire shop nearby to help.

Value Stem Image Credit: NAPA
Jan 25, 2025Openbay Staff