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how to stop tire deflation

Every Monday morning for the past month I have gotten in my car to go to work only to find my left front tire is low. No obvious reason for this and the tire has been checked twice for leaks so I can only assume there is a prankster in the neighborhood who thinks this is funny. I know the damage could be much worse, but I'm running out of quarters. Short of spending the entire weekend in my driveway, I cannot think of a way to get this to stop. Any ideas?
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Comments

  • edited September 2010
    If you think it's a prank, change the way you park so a different corner of your car is facing away from your home, assuming the prankster is hiding while doing this. You could also either rotate your tires or flip-flop them side to side, noting where the previously left front wheel was reinstalled. If the problem follows the tire, it's the tire. If it stays on that corner of the car, it's mischief.
  • edited September 2010
    Do you park close to the curb? If the tyre is tight against the curb, it could be causing the leak. I once was being driven mad by intermittent leaks, until I was walking away from my car and I heard the leak.
  • edited September 2010
    How thorougly was the tire tested?
    I ask because there are many tires out there with defective inflation valves, due to poor-quality Chinese-made equipment.

    Try putting a thick soapy solution on the valve after removing the valve cap. Put the solution on more than once if you have any doubts about what you are seeing. You just might find that the air loss is coming from the valve, rather than from the tire itself.

    Aside from deflation issues in general, I want to also focus on your other statement, namely, "I'm running out of quarters". That would seem to imply that you are driving to a gas station every time that you need to inflate your tires. In the long run, you would be much better-off if you bought your own tire inflator that you plug into the cigarette lighter socket. This will actually save you money in the long run, and is a whole lot more convenient than driving to a gas station each time you need air.

    Additionally, you will wind up with much more accurate tire pressures. The simple act of driving the car to the gas station temporarily raises the pressure in the tire, thus giving you an inaccurate inflation pressure. What seems like proper inflation at the gas station will actually be anywhere from 2-4 lbs lower, once the tires cool off. Tires should always be checked and inflated when they are cold (before the car is driven for the day) if you want accurate inflation pressures.

    Also, just by driving the car to the gas station while the tire(s) are underinflated can cause damage to the tire's sidewall. A badly deflated tire should NOT be driven on, and the obvious way to prevent that situation is by inflating it yourself, without having to drive the car.
  • edited September 2010
    You can get air valve core replacements at almost any auto parts store. The tool to remove and replace the core and the replacement core will be less than $10. Don't do it until you are next to the air refill pump.
  • edited September 2010
    It's easy enough to rule out a prankster. Check the pressure on Saturday morning, Saturday evening, Sunday morning, and Sunday evening. If it's going down steadily, it's a leak.

    Since you mention quarters, I'll assume you're driving to a gas station on that tire. That will quickly damage the sidewall and make the tire unsafe, so you'll want to stop doing that.

    You should be able to find the leak by spraying soapy water over the tire and looking for bubbles. If you really can't find it, have a local tire shop put in a new valve stem and clean up the bead area to see if that makes a difference.
  • edited September 2010
    It could be a bad seal around the rim too. Have them check that if they haven't.
  • edited September 2010
    I was having problems with a tire on my Civic awhile back, it seemed fine one minute, then coming back out after eating it was completely flat. Sears tried 3 different times to find the leak(they were the only place open on a Sunday morning and I returned there the other times since they'd done it before), on the 3rd time, they said that I should take the tire back where I got it and get a refund or replacement. They dunked it in water and resealed the bead each time to no avail. A relative suggests taking it to his mechanic and having him look at it, after I had already ordered my new rims and tires. We get there, the guy pumps the tire up almost to the max on the sidewall, and he finds there's a small hole on the rim as well as the tire that was leaking. He patched the tire up for me and sent me about my way.
    If your car is old enough, you may have a rusted hole in the rim itself, or a VERY tiny hole somewhere. If they are old aluminum rims, then they've probably become too porous and are leaking
  • edited September 2010
    It's NOT a prankster.

    Consider: you ALWAYS have a low tire, it's ALWAYS the same tire, and it's NEVER completely flat.

    That would mean that a "prankster" would need to be:

    1. Sufficiently dedicated to the prank that he'd keep it up for a month.
    2. Not mean-spirited enough to ever leave you with a flat you can't drive on.
    3. Sufficiently OCD to always target the same tire.

    It would seem vanishingly few people would have all 3 traits simultaneously. At least, someone dedicated enough to flat your tires every week for a month is likely mad enough to flat ALL 4 completely.

    Oh, and if you can REALLY think of someone with all 3 traits...have the tire in question rotated, while away from the house (where the supposed prankster wouldn't see it happen). If the problem moves with the tire, it's definitively not a prank.
  • edited September 2010
    Tell us about this "checking for leaks" procedure.

    Why don't you swap in your spare tire?

    What have you done to your neighbors?
  • edited September 2010
    You didn't give the year of the car. It is possible to have corrosion on the metal wheel itself. This can lead to very small air leaks that are hard to detect, especially if the guy checking is looking for something obvious like a nail.

    Have the leaking tire taken off the rim and have the rim cleaned and any corrosion sanded off. Remount the tire with a new valve stem. This should take care of your problem. I don't think you have a prankster. I had a tire do exactly the same thing and it was corrosion on the wheel as I described.
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