Had this tubeless setup for about 4 weeks and didn’t have any issues with losing pressure until earlier this week. Started noticing drops in pressure overnight or every two days until today when it dropped almost 40psi overnight.
Already removed the valve core, put it back again making sure it is adjusted, but it is still leaking.
Do I need to fully replace the valve core and stem? What could be causing this?
by chewmuch
3 Comments
Prestas suck.
When you removed the valve core did you clean any dried sealant gunk from it?
I’ve had a similar issue where a small ring of sealant dried around the black seal of the valve core. It made it so that the core was being blocked from sealing itself properly. When this happened to me air leaked when the core was open and it leaked a bit when it was closed unless I tightened it a lot.
Not sure if this explanation made sense, but I’d recommend cleaning the core if there is sealant on it. Inspect the black seal when doing so and make sure it’s not damaged. If that doesn’t fix it, just try a new core. Worst case scenario I think you would only have to replace the valve core, which is cheap and easy. It’s useful to have a few on hand. I can’t imagine you would need to replace the stem for any reason.
Maybe you made a tear on the rubber sealant of the core. I didn’t see you mentioning if you are using liquid sealant in the tires, this may do the trick, but it’s a hacky quick fix.
I would just remove the whole core first. If it wouldn’t help – whole stem.