Finding a slow leak in a tire can be tricky business, especially if you can’t find an easily visible screw or nail head. I like to use a simple mixture of dish detergent and water in a spray bottle to find a slow leak. You can also use a dunk tank which is what most service stations and tire shops use, but the spray bottle is easier to use and I’d wager that you have a spare spray bottle lying around while a dunk tank might be hard to come by.

Most tire leaks are caused by a foreign object piercing the tread and inner wall of the tire. I’ve seen screws, nails, shards of metal and glass, small tools (and larger ones!), animal bones (I hope…), and just about anything you could imagine…I should write a book. Because of this I like to focus on the tread of the tire first, spraying a section and looking for a trail of bubbles to build. After the tread, I look at the sidewall, followed by the valve stem area, then the bead.

The leak in this tire was corrosion between the wheel and the tire. Steel rims (wheels) tend to rust while aluminum alloy wheels tend to corrode. To fix a problem like this, you’ll have to remove the tire from the wheel which takes a tire machine, so this isn’t your usual weekend warrior job.

Using a standard wire brush or a wire cup on a drill or die grinder works well to clean up the corrosion. You can apply bead sealer if the corrosion is really bad. Unfortunately, it’s very difficult or impossible to stop corrosion like this. It occurs when the clear coat begins to come off the wheel and the alloy reacts to the air. Much like rust, once it starts it’s hard to stop.

Check back every Tuesday for more handy tips like this and every weekend for tech articles and project car updates. Happy wrenching!