Quick tubeless question for newbie

I’ve just inherited some mavic tubeless road tyres.
I understand that if I have a puncture that I can’t seal or repair with an ‘anchovie’ then I will need to use an inner tube to get me home.
My problem (I think) is that my tubeless valve rim screw is really tight, I can’t undo it with my hands in the garage at home. Should I loosen it now at home so that I can unscrew it out on the road? How does it maintain the seal if it’s looser?
Thanks Tubeless gurus.

You shouldn’t need it to be any tighter than finger tight, so I would loosen it now. It should still maintain the seal fine.
If its not maintaining the seal when finger tight then the issue is likely to actually be with the rim tape round the valve hole. If that is slightly ragged then it won’t hold air properly and it will end up causing a slow leak. This often happens if the hole in the tape was made using the tip of a knife - the edges of the slice tear under pressure. If the hole in the rim tape was made using a pin or a skewer (then pushing the valve through) then it should be fine


Thanks - will gently loosen with some pliers…

Solid response here. If you do loosen the screw you might notice it start leaking or perhaps the valve itself will twist in the rim. Just do the shake method with the valve at the bottom of the rim and it should seal up.

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and if in doubt, just add more sealant

Having taken them off with pliers - I think the locking ‘nut’ was clogged with sealant, rather than just too tight.
Any tips on how to avoid this - I presume clean after each sealant added etc?

Given that that bit should really be “outside” the system, so not exposed to the sealant, you may have sealant leaking through the valve hole in the rim tape. It might be worth checking the condition of the rim tape around the valve hole - are there any small tears around the edge of the hole? If yes, either retape the whole rim or just put some tubeless rim tape over the 6 inches or so either side of the hole. Re-pierce the hole - best way to do this is to either use a small soldering iron or to heat the tip of a metal skewer up so that it can melt through the tape when you push it through - this will help avoid tearing (that said, I usually just stick a cold skewer through).
Generally, if you’re adding the sealant through the valve make sure that you then move the valve to the top of the wheel before inflating as this will help clear out the sealant from the valve.

There’s no tape - it’s a mavic UST kysrium rim -but I might add some over the hole.

I presume the three ‘loose parts’ of the valve go outside the rim?
Top tip about the valve at the top when inflating - I learnt that the hard way when I first got them!