Tubeless valve leaking

[Janluke]

My Kenevo has been stood for a while(waiting for bigger spring) and the tyre was flat, pumped it up but air coming out of the valve as quick as I'm pumping it in. Any quick fixes before I remove/refit/replace

 

[eabmex]

if it is leaking from the base ju can try to tighten the nut (most obvious), normally just by hand or if you decide to use pliers be VERY careful not to overtighten, if the leak is from stem when you remove the pump you can remove the core and try to clean it (better to replace it).
Another point to consider is if you are using the original Specialized stems they do have an o ring that might be damaged, you will need to pop the bead to remove it to check

 

[Slowroller]

Don't tighten it with pliers or you won't be able to get it off without pliers in the event you need to in the field. I found that out the hard way. Finger tight is good.

I'd try to splash some sealant around the valve and see if that seals it. You might need more sealant if it's been a while as well. If all else fails, pop the bead at the valve, remove it, brush the base with some sealant and then reinstall. Which is a good idea when installing the valve in the first place.

 

[Maxb]

Plumbers ptf tape works well pop the valve out put a few wraps on this normally works. Also check your rims tape as this can also cause simular leaks