Valve stems - how tight?

[Guest]

My recently replaced front tire seems to lose air over time. I have to top-it-off every few days or so, depending on how much I ride...

I went tubeless this time (same as the rear) & don't want to pull it back off & put a tube in. I gave the tire shop a brand new OEM valve stem to use, and when I just now checked how tight it was installed in the wheel, I was surprised to discover it was only finger tight!!

So, I put a wrench on it and tightened it up considerably. I can go more with it, but I thought I'd ask for recomendations about exactly how tight it should be. I'm optimistic this will solve my losing air issue...

However, with that said, I also checked the rear tire valve stem and found that one to be essentially finger tight as well. The rear tire was installed last year (again, with a new OEM stem) and does not lose air.

[JEEPRUSTY]

My wheels use fancy pop in place stems.
No tightening necessary and they do not move a bit.

I would suspect the size stem they used is wrong.

[Guest]

My wheels use fancy pop in place stems.
No tightening necessary and they do not move a bit.

I would suspect the size stem they used is wrong.

I supplied the stems, they're OEM ones.

[JEEPRUSTY]

I supplied the stems, they're OEM ones.

Do tell....... Shrinkage and age? Maybe the internal bit of the valve is bad?

[bwringer]

The OEM-style stems are threaded and use a nut with rubber seals. You can't install rubber stems unless you drill out the holes.

The rule of thumb with rubber seals and gaskets is that you want the rubber to compress by 1/3.

This doesn't take a lot of torque. Under-tightening or over-tightening can cause leaks.

If tightening them a little doesn't help, you'll need to remove the tires so you can see how much the inner rubber seal is compressed. You may need to replace the valve stems if they were installed incorrectly or if the seal is crushed, split, or damaged.

You can test for leaks with a little bit of a non-corrosive mild soap solution (do NOT use dish soap).

I hope this goes without saying, but this is not the place to cut corners in any way.

[Guest]

yes don't overtighten. i (controversial? ) put a tiny dab of silicone in there as well, unnecessary, but i couldnt come up with a reason not to.

[Guest]

I hope this goes without saying, but this is not the place to cut corners in any way.

Well, yes... this is why I went with OEM stems. I didn't tighten them so much they wouldn't budge, but I did crank 'em down a lot more than they were. When I tighten the lock nut, it still spins the stem.

Preliminary results from this morning are promising - no air lost, so I'm hoping this was the fix.

[Guest]

yes don't overtighten. i (controversial? ) put a tiny dab of silicone in there as well, unnecessary, but i couldnt come up with a reason not to.

I didn't install these stems, but if I did, I would have used a bit of grease as well...

[Guest]

So, just to close this thread out - since I tightened my "new" OEM valve stems I've not had either tire lose any air...

Problem solved.