A tire had a slow leak, possibly due to our lousy roads. I had taken it to a different facility, where they couldn't find anything wrong with the tire, so they did something to seal the tire to the rim, but it continued to leak air. I then went to Kerner's, (where I should have gone in the first place); they checked the tire and couldn't find anything wrong with it. However, there was some corrosion on the rim that could have prevented an airtight seal. They worked their magic on the rim to make it smooth again, then re-mounted the tire. I'm optimistic the leak has been satisfactorily fixed. Side comment: They could have very easily sold me a new tire, at $130+, and I never would have known it wasn't necessary. This is another example of their business ethics, i.e., they won't tell a customer that a new part is needed unless it really is.