Put new tires on my old John Deere Gator, its a 1998, so got 22 years out of the old ones. However, one tire kept going down and using a soap spray could not find the leak. Finally took the wheel off and put it in a tank. Leak was in the top side of the rim and leaking through a crack in the paint until I scraped it off to reveal a round hole (no rust involved so cannot figure where the hole came from unless it was a factory flaw). Now what, Yes I could weld it, but then would have to take the tire off, so since the hole was round I found a self tapping hex headed screw the right size and added a barn screw grommet to the bottom side, wiped some tire glue on the grommet and screwed it into the rim. No more leak.