This is a rather strange problem. Recently brought car to Sears for 4 new\ntires. About one week, later found drivers side front flat, leaking out of\nvalve stem. Installed donut and brought car back to Sears for a tire\nremount. A few days later, same thing on same tire.\n\nAfter the second time I noticed that the Hub Cap was putting quite a bit of\npressure on the valve stem, after re-installing the hub cap and driving a\nfew miles. Seems that the hub caps are turning on the rims, and piercing\nthe tire valve stems. I removed the hubcap from that wheel.\n\nAfter incurring one more pierced stem on a different wheel, I removed all\nthe hub caps from the car.\n\nAnyone ever heard of this ???????? Not sure whether I should bring the car\nto the dealer for this, as it seems to be a huge safety issue if it is\nhappening to others who have changed tires. Perhaps the wheel weights were\ndifferent from the factory????? . Any opinions on this?