Very slow tire leak
 

I have a Goodyear tire (really, the tube) which is leaking about 15 pounds of air pressure over the course of two months. This has been going on for several years. Since I have a compressor handy, it has always been easier to inflate the tire than to pull it apart - until yesterday.

I submerged the tube and particularly the valve section in water, but could not find a trace of air escape. With the tube out of the tire itself, it inflates very rapidly. However, I cannot get a pressure reading with any of my pressure gauges. I have inserted different cores into the valve stem, but with the same result. By depressing the top of the core, air will release, but slowly. Of course, it may be that an inflated tube by itself does not generate enough pressure for a reading.

I am going to reseal the opening where the metal valve stem enters the tube. Is rubber cement preferable to contact cement? The rubber cement bottle does not give any curing time (before re-inflating the tube), whereas my contact cement bottle shows seven days required for curing.

Or, am I missing something else?

Gordon

Houston, Texas

Re: Very slow tire leak
 

I had an almost identical problem about two years ago. I finally concluded it was the "rubber" itself that the tube was made of. That is, the whole tube leaked. I gave up on it and bought a new tube. Problem solved for $16.

Re: Very slow tire leak
 

I suspect the valve stem core isn't seated. Try tightening the valve core. There is a special tool available at the auto parts store if you don't have one. If it moves (even just a bit) you should be all set. If that doesn't work take the weight off the tire. Remove the Schrader valve core and take another you may have lying around or you can get a new one and swap cores and re-inflate. If it was the tube I wouldn't expect it to take a couple of months to deflate. Tim

Very slow tire leak
 

I have the core tool, and I have used several cores to determine if that might be the source of the problem. The nut for the bridge washer was snug when I removed the tube from the tire, but it was not totally tight (even though there was no sign of air when I water-tested the tube).

I am going to apply some contact cement at the base of the stem and tighten up the nut and re-insert the tube in the tire. I am still suspicious that it does not require much air to inflate a standalone tube, which is why I may not be receiving any readings from my tire gauges.

Gordon

Re: Very slow tire leak
 

It's frustrating for sure, and I have a couple tubes the same way. For sure the tube by itself will not show pressure on your guage, as it probably has less than a pound of pressure.

I would NOT use anything on the core to tube connection. Any cement or paste will allow the rubber to slip out of place much easier than if it's assembled dry. Many years ago I learned that the hard way on the rear rubber gasket of a Chevy V8 intake manifold. After 3 tries, an old timer in the shop wised me up.:D

Re: Very slow tire leak
 

I know you guys will probably think I am nuts but my tires were leaking also...have original stems on the tubes.

That was 5 years ago.

I put some of that Green Goo or what ever it is called in the tube...5 years ago...Have had no problems since with air leaking out of the tube.

BUT...The downside of this is when I go to remove the tube from the wheel and tire someday...I have a feeling it is going to be a frickin mess!

Pluck

Re: Very slow tire leak
 

A fellow in our club bought 4 new tires and tubes before we headed off on a long trip to Massachusetts for a New England Meet. He ended up winning the "Hard Luck" award because all four tires kept going flat on him. We couldn't find a leak anywhere. As 700RPM said, the tubes were porous, and leaked slowly from everywhere!

Re: Very slow tire leak
 

tire slime is another name - that stuffs just about only good for emergency uses and sealing the tires on things your trying to sell:p

Re: Very slow tire leak
 

Definitely use Walt Bratton's tubes and don't look back. Who cares about a few extra dollars you are getting quality.

Unless you enjoy flat tires all the time.

Re: Very slow tire leak
 

I had the EXACT problem with a tube I bought from someone other than Bratton's. I bought two of his tubes (so I'd have a spare) and NO MORE SLOW LEAK. As said above, buy Bratton's tubes and forget the problem.

Steve

Re: Very slow tire leak
 

I have the same problem...bought all new tires and tubes about 2 years ago...should have kept my 18 year old tubes that never leaked. All 5 of the new ones leak about 4 lbs in 10 days or so. I have tried replacing the cores, and tightening the valves, but nothing works. I suspect that these are some of the awful Chinese made products, made to inferior specifications. So far I just keep airing them up, but will need to replace with Walt's tubes down the road.

Very slow tire leak
 

Thanks for all of the good replies. Here is where I stand:

I talked to Walt directly, and he said that the all-rubber tubes were introduced at his shop about 8-10 years ago. Hence, the five that I bought with A&L stems should qualify.

I do not have a stem that is not mounted to an existing wheel. Hence, measuring inside stem diameters (without the core, of course) is not possible. But, for the one that I have (which is only slowly releasing air) out of the rim has the following dimension: a #35 bit is the largest bit that goes through the opeing just above where the core sits. That's 0.110", if anyone cares, so a 7/64" (0.109") bit also works. I am curious if anyone has a stem with a significantly larger i.d.

Yesterday I used some contact cement around the base of the stem and tightened the nut on the bridge washer real tight. After placing the tube back into the tire and inflating (the air went in as rapidly as normal), I still could obtain no pressure reading. Air will slowly pass through the core when the tip is depressed, but not at such a rate that will give a pressure reading. I am suspicious that this stem was originally drilled out to an undersize (but, I'm not telling Al...)

Gordon