Slow Leak Detection

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December 1, 2010

by Arthur Wagner, Kerrville, Texas

Sometimes a tire will develop a slow leak that’s hard to find. Often the leak is in the tire valve core, which is a tiny spring-loaded device inside the tire valve stem.

Frequently the leak is so gradual that it won’t immediately show up. Here is what you can do with a suspect valve stem core. Slide a small balloon over the valve stem and secure it with a rubber band. If the balloon inflates after being in place for several days, you have found your leak.

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  1. Glenn Shindler

    Always use valve caps to keep out dirt and moisture. I prefer the chrome plated caps with neoprene gaskets, which seal perfectly and therefore you will never have leakage past the Schrader valve and valve cap. Your slow leak is somewhere else – frequently at the base of the valve stem where it may not seal perfectly with the wheel.

  2. Pingback: Slow Tire Leak | All Wheels Blog

  3. Bob Sutherland

    I like to do similar testing of the tires and the propane system at the same time. We keep a spray bottle of around 50 percent dish soap in our maintenance cupboard, and spray down the tires, stems, and the propane parts. Pretty much any leaks will be easily found.

  4. keith mcquin-roberts

    Agree totally with Rick Fisher – have used that test for the past 4 decades.

    Valve extensions can have a similar problem. I had an inside dually forever slowly deflating – thought it was a tyre problem but removed the extension just in case. Hey presto – pressure loss returned to normal values, similar to the rest of the tyres.

    On pressure loss issues, my truck tyres always need more frequent inflation than my fifth wheel tyres. Trailer has metal valves stems, the truck’s are rubber.

  5. Earl Wickam

    I agree with Bin Anderson and Rick Fisher. I may try the balloon on the inside dual.

  6. Bin Anderson

    What a load of garbage. Rick Fisher has the right answer – throw away your balloon and rubber band.

  7. Rick Fisher

    Re: Slow leak detector,
    Put a little saliva on a finger tip and transfer it to the valve stem opening. The tiniest leak will blow bubbles.