Why am I losing tire pressure???

Last weekend we were planning on a mini-road trip over the highway so I did my regular tire pressure checking and found that my drivers side front tire was especially light.  It was showing 22 psi as opposed to its recommended 35 psi.  When I took a good look you could see that it was low, although it is hard to tell though with the low profile tires.  I headed off to the nearest air pump and filled her back up to 35 and kept a close eye on it for the next couple of hours.  There is actually one free air pump not that far from here at a locally owned petro-canada station, but they are few and far between.  The same station also provides full service gas pumping at no extra charge.

Since there was no air loss I decided to head out over the highway on our 300 km trip, with two stops in between to check pressure.  The pressure seemed to be holding up so I was praying somehow someone just let some air out of my tire and that was it.  I made it to my destination no problem and still with no pressure loss.  The next morning I checked the pressure again and it was at 28...... I knew I had a problem.  I was figuring at that point no big deal, just top it up, get back to town and plug the slow leak I had.

As soon as I got back home without incident I went to my local wal-mart to get them to check the tire.  They were good about it because it was 4:30 on a sunday, they closed at 5 but took me in anyway.  About 10 minutes later they paged me to come to the auto center, and I was figuring I was in for some bad news.  Sure enough there was a small crack in my rim that was causing the loss of pressure.  The guys told me I would probably need a new rim which brought a shiver down my spine since I figured it would be 300-400 for a new one.  You could even see a small dent leading to the crack indicating some major bump had to cause the damage.

I was trying to think how this could have happened and earlier the week I did hit some new pavement where they were doing road work in town, but I was only going about 50km/hr so it was possible but I didn't think likely that would have cracked my rim.  My son had told me he hit a big pot hole about 2-3 weeks ago so that was a likely culprit with the crack just getting big enough for me to notice the loss of air eventually.  Although I will never know for sure either way.

In my next installment I will let you know the cost of a new rim and how I hope to resolve this issue.....