This is just something that’s become a bit annoying. My bicycle pump has the connection that you screw onto the tube valve. What’s happened more frequently is I screw it on the valve, pump up the tire, then in the process of unscrewing the connector it unscrews the presta valve inner core hence flattening the tire again. Does this happen to others?
make sure you valve core is screwed in tight before pumping.
Park Tools has a “VC-1 Valve Core Tool” that will enable you to securely tighten it. The other alternative is to purchase and install non-removeable valve cores.
My tubeless valve cores fit a 12 ga spoke wrench perfectly. So, if you don’t have a speciality tool; something like that might work.
Get the little plastic tool to tighten. Go to your local home depot and buy a .99 roll of teflon plumbers tape and wrap the threads in a very small piece of this tape and then screw it into the valve hole. It will both seal and also keep the valve core tight.
Thanks for the feedback. I think I’ll get the tool to tighten it and use the Teflon tape.
Stan’s makes a quality valve core tool.
I am assuming you have a Lezyne, if so and have the new one with the gold chuck that has the button on it to release the pressure make sure you do so before unscrewing it.
If you have the original silver one you have to unscrew it from the tube first.
The issue with them is it seem the pressure build up in the chuck causes it to pull out the inner cores I had the same problem then bought just the new gold chuck and its works great now.
I am assuming you have a Lezyne, if so and have the new one with the gold chuck that has the button on it to release the pressure make sure you do so before unscrewing it.
If you have the original silver one you have to unscrew it from the tube first.
The issue with them is it seem the pressure build up in the chuck causes it to pull out the inner cores I had the same problem then bought just the new gold chuck and its works great now.
I have a Lezyne as well, and use the optional 90-degree press on head that comes with it. Also makes it easy to use on discs.
I’ve also gone to non removable cores, since I’ve had several work loose from vibration or from screwing/unscrewing valve extenders.