bleucamaro

I have a set of Pirrelli P7000's on 993 turbo twists and when I was about a block from work, the car started pulling pretty hard to the side. When I parked, I took a look at the tire and it was VERY low. After a couple minutes it was completely flat. I figured I picked up a screw or something, so I pulled the wheel off and filled it up then hosed it with water to inspect for leaks. . . can't find any. Then I let it sit a couple hours and it hasn't leaked down. I put it back on the car and let it sit another hour, hasn't leaked down at all. What could cause something like this? Is it possible It developed a slow leak and once it got under, say 20psi, it opened up a small crack that is sealed with added pressure and deflated the rest of the way.

I'm thoroughly puzzled.
Any help is appreciated.
Thanks.

Jim Michaels

Yes, strange. My first thought was that someone let air out, but you should have noticed it before almost arriving at work. Then I thought about a piece of grit or something somehow pushing the valve stem in. I guy in my wife's office recently came out in the morning to find his two rear tires flat. After finding no puncture in either tire, the tire guy explained that he had been driving with the tire pressures so low that the seals at the rim had broken and air had escaped. My wife just bought him a tire gauge for Christmas.

bleucamaro

I'm thinking this is similar to what happened here. The tires were all a bit low (aside from the flat one) at 24-27lbs, and the reason I see for this is the temperature difference that we've seen here in the past couple days (not super cold, but natural gas law still applies).

SilverSteel

Yeah, I was thinking someone let the air out and perhaps the bead was broken and the airl leaked out. Once filled, the bead popped back in place and no leak. I'm just speculating, but I'd take it to Discount Tire or equivalent and have them check it. Good luck on this one...

Rick964

I once had a valve stem work its way loose and lost pressure while driving. Stopped, filled the tire and found that any sideways force on the valve stem caused a leak, apparently at speed there is enough force pushing the stem to the side that it leaked.

gerry100

A friend had his tire go suddenly flay as he pulled into the garage after a DE session at thr Glen.

Turned out to be a bad valve stem.

Reason I'm lurking here is athe I've got a solid Yokohama es100 left front tire that loses 6-8 psi siiting in my garage fora few days. No signs of damage or puncture.

Noticed at my last DE, put the air in and the tire worked fine.

Like to get this resolved before the next DE. I'm thinking valve stem?

Any other ideas?