Valve stem caps
Valve stem caps perform double duty by keeping dirt out of the valve core and by preventing air loss if you do have a small piece of dirt lodged in the valve core seal.
What is a valve stem core?
The valve stem core screws into the valve stem. It has a spring-tensioned plunger and a neoprene valve seal. When you press an air chuck against the plunger, it opens the valve and allows you to add or remove air. However, if there’s dirt surrounding the plunger, you can accidentally blow the dirt into the tire and even embed the dirt into the valve stem core seal, and that will cause a slow leak.
Why tire caps are so important
First, they keep dirt from building up around the core plunger in the first place. Then, if dirt does get embedded in the neoprene air seal, the cap will slow down or prevent the escape of the air until you can replace the valve core.
How to replace a valve stem core
Purchase a replacement core at any auto parts store. Using a core removal too, unscrew the core until it starts to blow out of the valve stem. Then insert the new core and tighten until snug using the core removal/install tool.
©, 2021 Rick Muscoplat
Posted on by Rick Muscoplat