From: Paul@Houston.Texas   
      
   The Real Bev wrote:   
   > On 7/24/22 8:09 PM, Xeno wrote:   
   >> On 25/7/2022 10:59 am, The Real Bev wrote:   
   >>> On 7/24/22 5:45 PM, Paul in Houston TX wrote:   
   >>>> The Real Bev wrote:   
   >>>>> 2013 Corolla S with the original wheels, tires and pressure   
   >>>>> sensors. There are only 33K miles on the tires and the tread is   
   >>>>> just fine.Ever since I've had it (2016) a single tire loses air   
   >>>>> very slowly -- it used to go from 32 (or 35, I'm not real picky)   
   >>>>> down to maybe 24, and the light would come on.  A month or so later   
   >>>>> the same thing happened.  Time between lights is now between one   
   >>>>> and two weeks.   
   >>>>>   
   >>>>> Dealer said he couldn't see a problem.  (I have no actual proof   
   >>>>> that he actually looked.)  I have a nice plug-in tire pump (the $35   
   >>>>> one from Harbor Freight;  the cheaper one burned up rather quickly   
   >>>>> when I tried to pump all four tires) so there's no real problem,   
   >>>>> and I'm unwilling to load the tire up with slime, but I'd really   
   >>>>> like to know WTF is happening.  Sooner or later I'm going to need   
   >>>>> new tires and it would be nice to know if I need a new pressure   
   >>>>> sensor too.   
   >>>>>   
   >>>>> BTW, I really like the tires (Goodyear Eagle RS-A) -- excellent   
   >>>>> cornering on the road I take to go skiing.  People really need to   
   >>>>> be ashamed when they get passed by a granny in a 9-YO Corolla!   
   >>>>   
   >>>> If the manual tire gauge agrees with the pressure sensor then the   
   >>>> pressure sensor is ok.   
   >>>   
   >>> The red light just says I NEED AIR.  The gauge on the pump and on my   
   >>> nifty little talking digital one are never the same -- I've NEVER   
   >>> seen two gauges the same, in fact.  For one reason, you lose a little   
   >>> air each time you check.  I wonder if the sensor device itself has a   
   >>> tiny leak.   
   >>>   
   >>> Some of the tires have plastic caps, some not. I had a cap on this   
   >>> one originally, but I lost it a while back.  No difference.  I keep   
   >>> meaning to buy some of the metal ones with the core tool, but I forget.   
   >>>   
   >>>> You did not say if it is always the Same tire -   
   >>>> will assume so.   
   >>>   
   >>> Yes.  The others hold air for months with or without cap.   
   >>>   
   >>>> Every time I had that problem there has been a nail or screw in the   
   >>>> tread.  The left rear of my Kia had that problem for last two years and   
   >>>> I finally upped the air pressure to 40+ and soaped it.  Found the screw   
   >>>> and removed it with needle nose pliers and then plugged it.   
   >>>   
   >>> I'm sure that if the dealer (amazingly enough, and against everything   
   >>> I knew about buying used cars for the last 50 years, I bought the car   
   >>> from the dealer, and it was the first one I drove when I decided on a   
   >>> 2- or 3-YO Corolla -- I couldn't see a reason to NOT buy this one!)   
   >>> would have found something obvious if he'd bothered to look.  They   
   >>> used to do a free rotation with the discounted oil change, so there's   
   >>> really no reason he shouldn't have given it a visual inspection;  I   
   >>> didn't expect them to take it off the rim.   
   >>>   
   >>>   
   >> A *visual inspection in-situ* will not find a slow leak. All that is   
   >> doing is a scan for the obvious, like a *visible nail*. To do a proper   
   >> inspection for a slow leak, you really need to remove the wheel and do   
   >> an immersion test. A pressure leak that loses ~10psi over a week will   
   >> show as a bubble every now and then during the test. When I was a wee   
   >> apprentice, we had a water vat purely for the purpose of leak testing   
   >> tyres. The practice works.   
   >   
   > Works fine for motorcycle and bicycle tubes. Car tires, not so much.   
   > Easier to just pump the damn thing every couple of weeks.  Know anything   
   > about the effects of Slime on pressure sensors?   
   >   
   >> FWIW, your tyres are getting to the point where I would call them *time   
   >> expired* or, as they say, past their *use by date*.   
   >   
   > So I've been told, but I've never had tires "expire" from anything not   
   > involving tread, puncture or -- and this I regard as criminal --   
   > sidewall bubbles in the defective and obsolete tires the Cadillac (or   
   > maybe it was Ford, it was quite a while ago) dealer sold to my mom at a   
   > premium price and refused to replace, turning the problem over to   
   > Bridgestone.  My Ducati's tires held air for at least 20 years in spite   
   > of visible crackling on the sidewalls.  Probably more because I don't   
   > know when the previous owner bought them.   
   >   
   >> I have never had the   
   >> issue of tyres time expired, they are typically worn out in 3 to 5   
   >> years. I'd clock up 33 k miles in 2 years, maximum 3, so I've never seen   
   >> a tyre on any of my cars over 5 years old.   
   >   
   > They don't get much wear at 3K miles/year.   
      
   The tire pressure sensor is part of the valve stem.   
   It may not let you inject the goo.   
   But if it does it may goo up the sensor.   
   Rock Auto $30-$45.   
      
   If it is a nail / screw it may be difficult to find.   
   Could never visually find them on my cars.  Always had to over pressure   
   then soap bubble.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)