How to fix a leaky tire with a presta valve? You may have a leaky tire because the valve core on the inner tube valve stem shipped loose from the factory.

To fix a leaky tire in this case all you need to do is make sure the valve core body is tightened on the valve stem. Use some small pliers, a wrench, or a valve core remover tool specifically for this purpose.

You may also have unintentionally loosened the valve when using a screw on pump head. I would suggest getting a pump with an air hose that has a push on head and clamp, and try to remove the pump head in a straight direction when done to avoid bending the valve stem.

Why would you buy a tire tube with a removable valve core? A removable valve core can be useful for replacement in case of failure (leaky valve), for adding extenders needed for deeper wheel rims, or for using tire sealant (slime) on an existing tube.

The tire inner tube presta valve featured in this video is a Continental Race 28 bike tube.

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  1. You could just use teflon tape. You wrap it around the threads and just screw the valve in. You don't have to overtighten the screw then.

  2. Good video! Just a quick question for you Bike Blogger, I've noticed that the last few times when using the Joe Blow pump that we both have that it will hiss or leak air while I'm pumping. I'm still able to reach maxium tire pressure but it leaks the whole time I am inflating. Has this ever happened with your pump and would you know why this happens and what to do about it? FYI it never did this before and it is still practically brand new. Thanks BB!

  3. Can you get the valve core from a different tire and put it on another one??? I'm asking because my tire is missing the core so the air comes out… but I have a flat one nd I was wondering if I could take the inside of it nd put it on the other one??? Plz help.

  4. This makes no sense. If the replacement valves cost the same as replacing the entire Tube what is the point of purchasing valves? I've been replacing my tubes each time I change my tires, which I do roughly every 10 months. It costs me a little more to use new tubes but I don't worry about a tube failure from wear and tear.

  5. Thanks, BikeBlogger– your video helped me understand why my presta valve was leaking— didn't even KNOW there was a "core" that could become loose. Just tightening it did the trick. Thanks a bunch!

  6. Check this one out. Today I had a flat. I patched it and road away. Maybe 2 miles up, I go flat again. I was done! I had just put a new tire on and I was pissed. I got a ride home. Took the tube out and could not find a hole. I finally just put the tube back in and pumped it up (I figured I wanted to stretch the new tire because it's new and tight on the rim). It's been about 7 hours and the tire is holding all the pressure???? I rode it around the block and all is fine. If I wake tomorrow and it still has the air – the only thing I can imagine, is someway the valve opened and let the air out??? It's habit for me to close the valve, but maybe I didn't? Even if I didn't, why would it let the air out like that? I"m lost. I hate the thought of going for a ride tomorrow and having to call for another ride. We'll see, I guess.


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