One of my tires keeps losing pressure. Two different shops have assured me there is nothing wrong with the tire itself (nail, screw, slash) or the stem. The mechanic at one of them took me aside, told me had worked previously at a tire shop, and that they often had problems with chrome wheels corroding and losing the seal between the tire and the rim.
Here’s where it gets interesting: Two tire shops say this is bunk, one says they have to grind down the rim, the Lexus dealer says it’s a known problem and they in effect caulk each tire (for $200 for all four).
So, who am I supposed to believe? And what am I supposed to do?
Take off the wheel, spray the tire with soapy water (or even dunk it in a swimming pool if you have one), and look for the bubbles to see where it’s leaking.
I had this problem with an alloy wheel in the past. Cleaning up the corrosion in that area of the wheel fixed it for me.
I don’t believe that the wheels on your vehicle are chrome, but instead alloy wheels. And what you describe is very common with this type of wheel.
The son works for a GoodYear repair facility. And he’s their main tire/wheel installer, and he deals with this problem all the time.
What happens is the alloy wheel corrodes from moisture. This can cause leaking only at the bead or the entire wheel becomes porous. if the wheel is porous, there’s a special coating that’s applied to the inside of the wheel to seal it. If it’s a bead leak, then the bead is cleaned. If there’s pitting in the bead area, this is repaired with a special compound. This is then sanded to match the contour of the bead. Once the tire is mounted, it then is filled with nitrogen. Nitrogen contains no moisture, so no further corrosion of the wheel occurs.
After all the alloy wheels he’s had to repair because of corrosion from moisture, he’s a firm believer of nitrogen in the tires if they’re mounted on alloy wheels. Especially if they’re expensive aftermarket alloy wheels.
Tester
As Tester stated, pressure leaks from alloy wheels is a known issue, especially with certain brands.
Another thing to consider is the possibility of defective valve stems. There is an active recall for–surprise–Chinese-made valves that lose air and are considered to be a hazard.
Take a look at:
http://www.safetyresearch.net/advocacy/defective-tire-valve-stems/
How fast is the leak?
$200 is a stroke job. You only have one leaker so why all 4? If they do a good leak check, they will know where it is leaking unless the leak rate is very slow. If it is a chromed, steel wheel, then they can easily remove the wheel, deflate the tire, break the beads, scuff up the rim with scotchbrite pads and apply bead sealer, all without removing the tire from the rim. Any neighborhood garage can do this too and probably for less than $25.
I like Lions idea. Pick up a small children’s swimming pool and a lawn chair, pump the tire to max pressure on the sidewall (don’t forget to reset the pressure after you find the leak), throw the wheel with tire in the pool, sit back, pop open a beer, and watch for bubbles.
IMHO it’s foolhearty to start doing all sorts of things when you really don’t know where the leak is. Find the leak, then fix it.