I have a fairly good leak in one of my tires...
I pumped the tube up about twice it's size, put it in the basement sink with some soap. Walked it around the sink a dozen times and have not seen a bubble one.
Any tricks to finding a leak ? I even sprayed soap on it and went over and over it with my hands...nothing. Arrrg !!
Maybe add more pressure?
Possible you fixed the leak by removing and installing the Schrader valve.
I guess so, Steve. It's gonna look like a 9N rear tube soon !
It loses 10 lbs in about 5 minutes, surprisingly I can't find it...
I had the Schrader valve submerged and it was leaking from around a rim mount lug when installed.
Still nothing, still holding...
Have you pumped up the tube substantially, removed the valve and let all the air escape (hopefully along with any dust particles), then reinstalled the valve (or another one?), re-aired the tube, and checked again for a leak?
Most of my leaks seem to involve dust particles in the valve, which keeps them from sealing properly. Clean them out and works most of the time.
Just my 2 cents! Good luck.
Bob, I have checked this thing once and could not find a leak...
Put it back in the tire and it was audible. I have pulled the core a couple times dismounting the tire. It almost looked like a couple spots were pinched, but I can't see a leak. I'm afraid to put more air in it.
Like I said, it was leaking air out of a space where the lug is welded to the rim. Probably the only place to escape, when mounted.
I've patched many a dirt bike tube in my day, but ain't never seen nothing like this !
If it is a metal stem tube, I have seen them tear slightly at the base of the stem. The tear only leaks when there is a side load on the stem. With the tube pumped up, thy wiggling the stem around and see if a tear opens up and starts leaking.
It's a rubber valve stem and I wiggled it all around.
I found some good hot patches too, and was all gung ho...
It's still the same size as the picture, a couple hours later.
Well...an hour later !
If you pull the tube out again to ck for leaks use some soapy water. That usually works in finding leaks in tubes that only appear at high pressures. You have a leak that probably can't be detected unless you have at least 20lbs in the tube. And that's to much for just the tube by it self.
I had some new tubes that constantly lost air over time but had no leak. I got so tired of adding air that I put back old tubes with numerous patches and have had no problems since.
You are right about that Val S. I do remember haveing one of those slow leakers a few years ago and it was a new tube. Bought another tube and cured the problem. I just tired of messing with it.
But I did find a slow leak using soapy water in another tube. Patched it and it worked. It was caused by a pinch when I installed the tube.
Thanks everyone, nothing I haven't tried yet.
The tube is sitting in the corner, still about twice the size of the tire....I have the spare on and another spare, this is a much better tire. I guess I can wait till my brother goes to Hershey.
Very strange !
If it is a demountable rim, put the tube back in the tire and mount it back on the rim. Blow it up to 55 to 60 psi and dump the whole tire and rim in a basin of water. Let it sit there for 15 minutes or so to see if any bubbles come up and where they come from. If it is not demountable you could dump the whole wheel in the basin of water.
I don't know if this is possible with a Model T tire but I have seen this with other tubes in tires. There could be air trapped between the tube and the tire which escapes and makes it look like the tube is leaking.
Neil, your second thought is one I had. I did that once, thinking maybe air was coming from between the tire and tube... but it was losing pressure.
It's demountable, and I hear it leaking by a lug, I assume the only place it can get out.
BTW, it still is the size in the picture, about double the size of the tire !!
Is the pressure still the same, or dropping?
Don't be fooled by the amount of air that can escape from a tire after you mount the tube inside a tire and then inflate it. There is a lot of space inside there and that air must escape when the inflated tube expands inside the tire and rim.
I was fooled once into thinking I had pinched the tube so I took the tire off again to find a new tube with no hole! Good practice mounting the clinchers I guess.
Mounted it again, Sam Ting....I will peal the tire off the rim once more, when I have a new tube !!
I walk away defeated...well, drive away on the spare. I'm going for a put before it gets dark.
Dave, On one of my toys with A.C. I had a slow freon leak. What was found was the schrader valve was proud in the threads but sealed fine until the cap was installed resulting in a very slow leak. Just a thought.
I think that when the tube is out of the tire like you show in the pic, there's not enough air pressure to adequately indicate that the valve stem is the culprit. I've seen 'em hold 20lbs. of air for months on end, put them in the tire, pump 'em up to the prescribed 50-60 lbs. and voila...they leak. Just my worthless two cents.
Tim, I think that's the whole problem.
With the tube double in size, it only had 5 psi.
It actually lost about 20 psi in a minute after 50 psi. and mounted.
I just can't believe with that fast of a leak, I see nothing with it all swelled up. I had it apart 4 times...I'm a friggin expert !
I checked the valve stem, it leaks from around it and at the one lug, but spit don't bubble on the valve.
Dave, with the tire and tube assembled, mix some plain old dish washing soap with water, and with the tire inflated, coat the stem completely with the solution. I suspect you will find air leaking between the rubber of the stem, and the brass part of the stem, where they are supposed to be bonded. If so, you can try Steve Jelf's system of cutting the stem off, and replacing it with an old replacement stem. He has posted his system on other posts in the past. A stem leak like that will usually not show up at low pressure. Good luck! I owned a tire shop for thirty years, doing tires and mechanical work, and most of the hard to find tube leaks were in the stem area.
Looking for bubbles with the tube under water isn't the best way. Too much water tension to allow a small leak to bubble up.
Had a leaker like you, a new rubber stem tube, mounted and the tire went flat over time.
Pulled that tube. Looked all around the tube when lightly inflated and saw no marks, scrubs, or cracks.
So then put a fairly weak solution of soap/water in a spray bottle, the kind with the pump like squeeze handle, with a nice fine spray orifice.
About 5 lbs. air in tube, sprayed over places, looking for large bubbles. Around the valve stem plate, sprayed there. Now many little bubbles are natural from spraying on the tube surface. That process deposits the tiny bubbles.
But a leak with show a bigger... fatter bubble... that will grow as the air leaks from the tube.
That is the best way to find the leaking spot
See the bigger bubbles growing in line, like a caterpillar, leaking from a split at the sealing of the valve stem , the cause, poor sealing process by the mfg.
After all that screwing around, I looked one more time...
And found a BRAND NEW tube in my stockpile !!
About 20 minutes later and the tire is on the car and not leaking.
If the tire leaks it most likely has a hole in it.
Thanks Philip...AKA Cpt. Obvious ! lol
It was only flat on one side too !