[monteverest]

Just got a brand new UST Crosstrail yesterday and discovered air leaks through the valve opening (with valve inserted). However, squeezing a gasket onto the valve reduces or eliminates the leaks. Since I'm new to this tubeless stuff and don't know any better, should a brand new UST wheel leak through the valve opening when the gasket is not installed?

Seems very flimsy if it is because normal riding will eventually dislodge the valve. Mavic could have built an integrated gasket into the valve instead of relying on this ad-hoc seal. Thanks

 

[gonefirefightin]

it sounds like the o-ring isnt installed or the stem isnt seated in the plastic bead bed enough. are thery new? do you have the little bag of goodies with it? if so use the o-rings

 

[DirtyDog]

Yeah there should be some kind of rubber seal on the valve. I always use a bit of sealant in my tubeless tires - helps with the inevitable quick deflation and small punctures.

 

[TKCastle]

Take off tire and push valve from inside hard. You will feel it seat. make sure the valve ears are running along the inside channel.

 

[monteverest]

doing both seem to seal the leak but I still lose about 10lbs of air overnight - my guess is its coming out through the valve opening still. If it is the valve opening, wondering at this point if this is a factory defect or allowable tolerance. I'll have to call Mavic or the e-tailer and see if they can send a replacement.

 

[monteverest]

doing both seem to seal the leak but I still lose about 10lbs of air overnight - my guess is its coming out through the valve opening still. If it is the valve opening, wondering at this point if this is a factory defect or allowable tolerance. I'll have to call Mavic or the e-tailer and see if they can send a replacement.

thanks everyone for your responses --

 

[Arkayne]

I highly recommend using Stans if you aren't already because it'll cure all your sealing anomalies. Also, put some soapy water all over the bead area and your valve. You'll see your leaks that way.

 

[Mike B.]

Contrary to popular belief, that small o-ring is not for sealing or air retention but rather to prevent the presta nut from vibrating loose.

That said, buried in most tech manuals for UST wheels you'll find a note on putting some petroleum jelly (Vaseline) on the rubber base of the valve when inserting in the valve hole to help with slow leaks at the valve. It helps to create a more positive seal, not always required but helpful.

Oh yeah, throw some Stan's sealant in there for good measure too

Yes I realize there is plenty of room for innuendo there, go for it boys.