How To Fix A Leaky Tire Presta Valve Stem Valve Core Bike Blogger 

I have no idea who thought a presta valve would be a great invention!

Thanks for the advice; this stops me from buying a new bicycle to fix the problem.

Hands up anyone watching in 2024!!

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!

Perfect, thank you! This will save me having to replace entire tubes every time one of my valve stems gets bent. I wish I had thought to google this years ago.

Thank you for posting these videos I enjoy taking a lift on your commute as much as your tutorials.

*Schrader valves on bike inner tubes only support a max PSI of 65 so that's why the Presta valve was invented. Yep, they're a pain to maintain, however thanks to the presta valve we can put 120 psi in bike road tires and roll faster.*

So simple, i nearly chucked the tube but a little tightening fixed it. Thanks.

Thank you that solved my problem that I´ve been fighting with a lot. Now feeling pretty stupid not figuring it out by myself but main thing it´s now finally fixed!

THIS was exactly what I needed! Thank you and a thumbs up!

Good video. Before discarding an old damaged tube I always save the valve cores. Have a pill bottle full of them.

just a side note: when I went to release the presta knob to add air, the knob sheared off from the long stem that goes down the core. It happen twice on both the front and rear tube. If this happens to you, you can order new presta cores to replace. Just make sure your tube allows for replacement because some don't. but remember that you have to remove the old long piece of stem that is still inside the tube or you can end up puncturing the tube from within. this is what I did to find it quickly. 1. add the new core to the tube. 2. add air to the tube like blowing into a balloon. close off the stem. you just need enough air to be able to hear the long piece of stem floating inside the tube. 3. listen for it as you shake the tube slowly. Remember you want to make sure the piece inside drops towards the stem. 4. once you hear it, locate it by softly pinching the tube until you feel it. make sure you hold on to it. 5. As you are holding it, remove the new stem core that you installed earlier. 6. Now, there should be no air since you removed the stem core. 7. kind of guide the stem core piece towards the stem hole and feed it into the stem. 8. once you know that it's inside, tilt the stem downward and watch it fall out. if anyone has a better way to remove, then let us all know. in the 30 years of cycling I can't recall that I have ever had a Presta knob shear off from the stem core. kind of weird or just cheap tubes. they are from Specialized. The tubes are still good other than the presta valve breaking off. it took me no more than 5 minutes for the whole routine. If you would like a video, like my post and reply.

thanks!! Was thinking I needed to replace the entire tube, which I literally just replaced; this vid saved me hours of time, and about 20$!

Thanks for saving me from needing to return the tube. As others have stated - what a stupid design. I've had so many problems with the Presta valves over time.

TopTip - I have just removed my stem valve following puncture repair inspection revealed Soaps water suds at the tip. I wrapped a small amount of PTFE tape around the stem thread and replaced it. No more leakage 👍🏻

Thanks brother, just went and bought a pump and a new inner tube to find out it was the valve the whole times so this video came in very handy ❤️👍🏾

Incredible video….now I know exactly what to check for without automatically assuming that I need a new stem. Was puzzled why I couldn’t figure out how the stem was losing air.

Hi very good video I recently had got some continental tubes for my bike which is presta. I went out for a ride and thought what, tyre is flat not gone over anything these are brand new tubes. After walking home and next day taking cap off I discovered the valve had come out and stuck in the cap. Being new to presta I thought it must be a faulty innertube so complained to Amazon and they sent me out 2 replacements. Now knowing from this video that it was because the valve was completly loose, which caused the problem. It has given me knowledge and others who see this video who did not know. Thanks

Exactly what I needed to see. Thank you !!

Great, now we have to check two things to see where the leak is

There is another reason to remove and reinstall (the same) core -- sealants. Say you get a flat around 1h ride from home. You unscrew core, put some sealant into the tube, insert core back, inflate the tube, rotate the wheel, wait few minutes and you can get back home without entire procedure or removing entire wheel, changing tube, etc.

Helped me a lot! Thanks 😊

Thanks for posting. Useful to know.

Continental inner tube good quality and normally have same issue I just tight them up with spanner so simple when u know what ur doing

I love you, man! Loose friggin valve core!

I also have Continental tubes, I actually bought a bunch of them in bulks and I think that most of them have this issue of being not screwed strong enough because air escaping my tubes is a common problem. Thanks a lot for the clip! hope it helps, might update in a few months if it does.

Thanks, this was quite informative!

Thanks for the great vid. I'm not crazy about the freakin presta valves - what a pain. I'm going to try to tighten mine and see if that's the problem with air coming out quickly after I unscrew the adapter after using an electric air pump.

you just saved me the price of an inner tube. I'm used to schrader so didn't know this!

I will give that a try! Thanks!

Easy enough. The presta valve may have been slightly bent but my pump pulled the whole thing out. Here's hoping I can just replace the core. The tube was new.

Thanks , just what I neded to know !

So Simple, Did Not know about that, Thanks.

Careful threading these!

Thanks for the video tips

My tube had a slow leak. Cured it by screwing in the valve core tighter. I guess it loosened by my overdoing it when I loosened the sleeve to pump up the tube. I think the leak path is along the threads between the core and the stem.

Great video, thanks

Thanks for sharing

Thanks! Problem solved.

If you run tubeless, the valve cores can get clogged or fouled by sealant. I replace cores from time to time. It’s a 2 minute job. But I have the tool.

Thank you this was so so helpful!

Many thanks

Respect now i know how to put puncture proof tire solution in to it

Just a got a used road bike with Presta valves and one tire had a slow leak I knew NOTHING about Presta valvesso you helped me out big time. I won't buy a new tube until I try your trick Mine had no caps, should I buy some? Thank you again .

Great video. Had this issue and didn't realised you could remove that part on a Presta (more familiar with schrader valves). You saved me buying a new tube.

These type of valve are meant to be used when you put sealant for tubeless tires.

شكرا لك اخي الكريم

Just Make sure the core is tight or get tube without removable cores if there available also I think the hold air a lot better JMO

That bottom security "screw" is that right way of that? Or you put it up side down I bought bike with that tyre and I am not sure

OK I ran into this one this afternoon on the wife's bike and was unaware about the valve core possibility. But I removed the existing inner tube and inflated it outside of the wheel and it keeps pressure. Then I installed a brand new inner tube fresh out of the box and it does the same thing - on an inner tube that's brand new! Looking, the rim tape on the wheel looks intact/good and the wheel itself doesn't seem to have any sharp edges that would cause it - I've been using presta valves since the early 2000s and now I have two "bad" ones in one hour? One on a brand new inner tube? Tire looks hardly ridden as well.

Great video...that's exactly what my problem is (2nd time it's happened too). Now I know what I need to do :-).

Let's hope the next time I get a flat and change the inner tube for one that unknowingly had a leaky valve I don't spend ages trying to find where on the 2nd tube it was punctured.

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!

ok so the top of mine that has the twisty thing broke off, can i put it back in?

the air would be entirely gone overnight while it's Ok even the bike is on the road for few hours, this has continued for few weeks. Wondering if it's due to presta valve or a hole in the tire, thanks if you have an answer to it.

Well how the heck do you fix it if it’s not removable? Could you please do a video on that?

I'd rather buy a new tube for 8$ that will actually work.

Thanks, process of elimination.

a spoke key makes a good tool if you have one the right size

I think some valve cores cannot be removed. I have just tried to remove a GOOD one from a tube to be used to replace a bad one of another tube temporarily, and I broke the core. The tube is useless now.

Thanks for your video. The presta valve broke off of my back tire. I picked up an inner valve core to replace it, but I can't get the original one to come out. It appears that the valve core and the stem are one piece. I can't unscrew it. Could this my problem? Are some made this way? Cuz if it is, I need to bring the bike into a shop. I'm not real bike tech savvy, but I try smaller fixes when necessary. Any advice would be greatly appreciated!

How do I fix a bent end?

I can hear mine leaking. But I cannot get it to turn out. It seems the whole stem turns not just the core. There is nowhere to grab the stem to stop it from turning. Maybe I should use a cloth and some pliers. Should it be this hard?

I bent the presta valve core after incorrectly pumping tire. Tubeless tire. Just need to find out what presta valve is appropriate for my tubeless tire.

I overtightened the valve nut and the valve stem is now leaking a lot. Do you think this would require a new tube with valve?

THE SECURING VALVE NUT HAS BEEN INSTALLED UPSIDE DOWN ! THIS MEANS THE WHOLE VALVE WIGGLES ANS MOVES AND EVENTUALLY THE TUBE SPLITS AT THE SEAT OF THE VALVE.

After i inserted the pump head, this valve leaking when pumping in air. When i remove my pump, no leak again. Was it deal to the same problem? Valve loose? Thanks

I never knew

Hi BikeBlogger. I have a little spanner that fits the valve.

I didn't that because I've thrown away 3 inner tubes. But I did question after the 3rd inner tube what was going on?

I think my Presta valve may be leaking. I am losing about half my pressure in 24 hours. How do I tell if my valve core is removable/replaceable? Do only the removable ones have flats on for pliers? Thanks for any help. 😘

Mines leaking from the round wide part that is touching rim. What’s the fix for this? I keep turning it thinking it’s tightening but still leaks air

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.

What I hate about those removable conti valves is, that they came loose far too often, unscrewing my Lezyne pump after inflating the tyre...forcing me to start all over...

I think it is moraly right to steal your friend's stem valve core. just saying

Cheaper tubes won't unscrew like that: they will break off.

Before you do anything just put the valve in some water and if it bubbles you know the leak is coming from the valve.

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.

both tires with Presta valves will NOT unscrew as shown on this video (from a Continental CityRIDE)

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.

hope it turns out to be just that , saves a few dollars ...

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.

Should you just buy a new intertube??

A valve core removal tool makes it a lot easier fyi

So, to clarify, if it's not the valve core it's the inner tube.

I always have trouble with theses valves for years now hate them

tightening It didn't fixe it for me,

My valve was wonky, I literally hit it with a hammer and it seems to have stopped leaking now!

What about if you forgot to tighten the valve into the wheel before adding sealant? I've just fucking done it without thinking and now the wheel loses air slowly

This MUST be whats wrong with minw, but it keeps happening, only when riding the bike, otherwise it stays up

It's not uncommon for a tube to ship with a loose core...any time I buy a tube I check the core tightness before I install the tube or stick it in my saddle bag.

Why are presta valves even a thing when we already have schrader? Presta just seems more leak-prone, fragile and unnecessarily complex.

They always leak. Leave bike alone a week and have to reinflate again

Some of these poorly designed valves come fully made with no integral parts. Schrader valves every time.

Okay so who invented this Presta valve thing and why even is it a thing. the thing sucks ass so many problems I thought this was like some revolutionary type of thing at first

Bad design... hufff

Presta is truly one of the worst inventions ever. It is the bane of all bike riders. It is fragile, prone to bent and brakes quite easily. The bike tires take the most abuse and they "invented" one of the most delicate and crucial part to go alone with that abuse. SOMEONE PLEASE come out with an alternative already.

Thanks dude. Ruined the stem. THUMBS DOWN

These continental innertube valves are the worst design on the entire planet absolute nightmare.

Presta sucks so much. Why is it even on the market