17/12/2025
If you’re using tire sealant for the first time, you’re not just fixing a flat—you’re also learning how your tires work!
One question we hear a lot is, “What is a valve core?” If you don’t know the answer, don't worry. You are definitely not alone. Many of our customers ask this same thing when they first read our instructions.
What is a valve core?
The valve core is a tiny metal part that screws into the center of your tire’s valve stem (the tube where you add air). It has a small pin with a spring inside.
This little part is very important: it is the only thing that keeps the air inside your tire! Without it, all the air would rush out immediately.
How does it work?
Letting air out: If you push down on the tiny pin in the center, the valve opens and air escapes. You can do this with a pen, a key, or the button on a tire pressure gauge.
Putting air in: When you hook up an air pump, the hose automatically pushes that pin down so air can flow into the tire.
Using it with Slime
To put Slime sealant into your tire, you need to move the valve core out of the way first.
It’s very simple to do:
Look at the black cap on your bottle of Slime. It has a built-in tool made for this job.
Use that tool to unscrew the valve core and pull it out.
After you squeeze the sealant into the tire, just screw the valve core back in.
That’s it! You are now an expert on valve cores.
