A flat?!

[somegirl]

I'm not sure where my tire is leaking from but I have a suspicion it's the valve core. The reason I suspect the core is the tire had no problems until one night I checked pressures/added air. Rode it that night, parked it, and the next morning it was DEAD FLAT. Filled it up to 40 lbs and sprayed the entire wheel and tire down with soapy water - no bubbles anywhere and I was looking HARD. After that it held air fine. Now, after checking pressures a few more times since, it's losing about 3 lbs. per day.

We recently had a slow leak on a car tire, lost about 6 PSI per day.  We jacked it up and sprayed the whole thing with soapy water, including the valve stem, and couldn't find the leak. 

Since the car was still under warranty I took it to the dealer.  They first told me the pressure was fine so they didn't think there was any issue (I had refilled it that morning before driving there), next they told me that my leak was because the cap was off the valve (we were leaving it off to make it easier to fill every day). 

Anyway, after I gave them what-for on the phone, they took the wheel off and on the 3rd try in the dunk tank, they found a hairline crack in the rim and replaced it under the warranty.

Just another data point for something to look out for.

[Desmo Demon]

We recently had a slow leak on a car tire, lost about 6 PSI per day.  We jacked it up and sprayed the whole thing with soapy water, including the valve stem, and couldn't find the leak. 
<snip>
Anyway, after I gave them what-for on the phone, they took the wheel off and on the 3rd try in the dunk tank, they found a hairline crack in the rim and replaced it under the warranty.

This reminded me of an issue I had a few years ago with a tire leaking. Some days the tire held air fine, and other days it would drop 10-15 psi overnight. I fought it for a few weeks until it finally stopped. My theory is that there was a small piece of dirt that was hanging out around the valve seal. Some days the dirt would interfere with the valve seating and other times it wouldn't. Eventually, it must have broken free and was either blown into the tire while refilling it or blown out with escaping air.

I once had an opposite issue.....I couldn't put air into the tire. That wound up being the metal pin for the valve had gotten bent, so when I pushed it down with the air hose, it wouldn't break the seal and didn't allow air into the tire. I was running the compressor at 40-60 psi, so maybe I should have bumped it up to 120+ and just forced the valve open. 

[MendoDave]

We recently had a slow leak on a car tire, lost about 6 PSI per day.  We jacked it up and sprayed the whole thing with soapy water, including the valve stem, and couldn't find the leak. 

Since the car was still under warranty I took it to the dealer.  They first told me the pressure was fine so they didn't think there was any issue (I had refilled it that morning before driving there), next they told me that my leak was because the cap was off the valve (we were leaving it off to make it easier to fill every day). 

Anyway, after I gave them what-for on the phone, they took the wheel off and on the 3rd try in the dunk tank, they found a hairline crack in the rim and replaced it under the warranty.

Just another data point for something to look out for.

And that explains why you are a carrot that looks like a hummingbird now!?!

[somegirl]

And that explains why you are a carrot that looks like a hummingbird now!?!

[orangelion03]

Thanks for the various thoughts in this post.  I punctured my rear tire yesterday and repaired it with a mushroom plug to get me home.  I was going to just have the tire patched internally, but after reading this and looking at the proximity of the wear bars on the tire, I opted for a new one.

That being said, I repaired a few punctures in car tires that were later used on the track and never had a problem with the plugs failing (the gluey-wormy type).