I have heard that if a tire goes flat, is not safe to use one of the products such as "Fix-a-Flat. Is this so?Yes and No! On the yes side, it would be a great idea, especially if you have a flat at night or in bad weather .However, if the inflator is flammable, you must warn the tire shop that the tire has tire sealer inside. There is a warning sticker which comes with the cans of the flammable stuff which you’re supposed to stick on the rim to warn the tech. There have been some pretty serious injuries caused by a spark setting off the flammable mixture when the tire tech breaks down the tire!
On the no side the tech must clean all the goop out of the tire before it can be repaired. Some shops may want to charge you extra for this service. Also, the tire sealer won’t help if you have a blowout, as it only can seal up relatively small leaks.
