When you can't find a slow tire leak, inflate the tire fully and work through every leak point in order with Bubble Check: valve core, valve stem or TPMS stem, the tread, both beads, and the wheel itself, including the inner barrel. Give each spot time, because a slow leak can take a while to show. If nothing bubbles, recheck the pressure after a day at a similar temperature; a pressure drop you cannot find may not be a leak.
How does it show up?
- The tire needs air every few days or weeks, with no visible damage.
- A TPMS warning keeps coming back.
- Earlier checks found nothing.
Where do you spray Bubble Check?
- Valve core: cap off, spray the open end. Valve core guide.
- Valve stem or TPMS stem: spray the base, flex rubber stems. Stem guide.
- Tread: spray one section at a time and rotate. Tread puncture guide.
- Both beads, including the inner bead that faces the car. Bead leak guide.
- The wheel: inner barrel, spoke roots, and face. Porosity and crack guide.
- Sidewalls, both sides.
- If the tire is on the vehicle, lift it or pull the wheel so you can reach the inner side.
What do the bubbles look like?
- The first light foam from the spray settles within seconds. A leak keeps building in one spot.
- Very slow leaks may show as fine foam that grows over a minute or more.
- Some leaks open only when the tire flexes. Rotate and push on the sidewall while you watch.
What do you do next?
- If you find it, follow the guide for that leak type.
- If nothing bubbles, set the pressure, note it, and recheck after a day at a similar temperature with a gauge you trust.
- Remember that cooler air lowers tire pressure on its own, so an overnight drop in cold weather may not be a leak.
- If the pressure keeps dropping, demount the tire, inspect the inside of the tire and the bead seat, and test the wheel again with the tire off.
How to run the check
- Inflate the tire to its specified pressure. A soft tire may not push enough air to show a slow leak.
- Spray Bubble Check on the area and give it time. A slow leak can take a little while to show.
- Watch for bubbles that keep forming at the same point. The first light foam from the spray settles; a leak keeps building.
- Mark the spot with a tire crayon before you wipe the area dry.
About Bubble Check
Bubble Check is the CHAOS Moto spray-on tire leak detector. It comes in a 32 oz bottle with a trigger sprayer, so you check the tire on the wheel with no dunk tank needed. Shops use it to pinpoint valve and bead leaks and for TPMS stem checks. See the Bubble Check page or where to buy. Bubble Check is not currently sold on Amazon.
Common questions
Why can't I find my slow leak?
It is often on the inner bead or inner barrel, the side facing the car, or it opens only when the tire flexes. Check those spots and give each one time.
Can cold weather make a tire look like it has a leak?
Yes. Tire pressure drops as the air cools, so a drop overnight in cold weather may not be a leak. Recheck at a similar temperature.
Do I need a dunk tank to find a slow leak?
No. Bubble Check is sprayed on the tire and wheel, so you can check every leak point in the bay with no dunk tank.
More leak types in the Leak Lab. Related: how to find a slow tire leak and wheel porosity or a cracked rim. Questions: sales@chaosmoto.com or 480-829-7888.