A TPMS light comes on, the tire looks fine, and now a tech has to figure out which of five possible leak points is actually losing air. The valve core. The valve stem base. The TPMS sensor grommet. The bead seat. A pinhole in the tread. Dunking a wheel doesn't answer that question fast, and on a lot of TPMS jobs you can't dunk the whole assembly anyway because the sensor housing shouldn't sit underwater. That's the exact spot where a spray leak detector earns its keep over a tank.
Why TPMS leaks are harder to isolate than a plain slow leak
A standard slow leak usually has one cause: a nail, a screw, a bead that never fully seated. A TPMS wheel adds three more failure points that live outside the tire itself. The valve core can lose its seal. The rubber grommet where the sensor passes through the wheel can crack or shrink with age. The sensor-to-wheel mounting nut can back off just enough to break the seal without anyone noticing. None of those show up on a visual inspection, and none of them show up in a dunk tank without pulling the whole wheel off the car and finding a way to submerge it without soaking the sensor electronics.
Bubble Check skips that problem. Spray it directly on the valve core, the stem base, the grommet, and the bead seat with the wheel still mounted, still under pressure, still in whatever position it's in on the lift. Bubbles form right at the leak point in seconds, so the tech sees exactly which of the four or five spots is the actual culprit instead of guessing or replacing parts one at a time.
Where to spray, in order
Start at the valve core, since that's the single most common TPMS leak point and the cheapest fix if that's all it is. Move to the stem base and the grommet where it meets the wheel. Then the bead seat, all the way around, particularly on wheels that have been off and on more than once. Last, the barrel of the tire itself if nothing upstream shows bubbles. Spraying in that order means the tech finds the cheap fix before assuming the expensive one.
Bead and mounting leaks after a TPMS service
Every time a TPMS sensor gets serviced, the tire comes off the bead. That's a second chance for a bead leak that has nothing to do with the sensor at all, and it's easy to blame the sensor when the real problem is a bead that didn't reseat clean. Running Bubble Check around the full bead seat after any TPMS service catches that before the car leaves the bay, instead of coming back as a comeback with the customer convinced the new sensor is bad.
32 ounces with a trigger sprayer covers a full shift of TPMS diagnostics without refilling, and the bottle sprays low-foam so the bubbles that form are actually at the leak, not just foam drifting across the whole wheel. Bubble Check ships by the case, with volume pricing available at higher order quantities. Ask your rep for the current tier.
Frequently asked questions
Can Bubble Check be used with the sensor still mounted?
Yes. That's the point of a spray detector over a dunk tank. Spray the grommet and mounting area directly with the wheel on the car or on the balancer, no disassembly and no risk of soaking the sensor electronics.
Will it damage the TPMS sensor or the rubber grommet?
Bubble Check is water and surfactant based, the same category of solution used for leak checks across the industry. It's not going to degrade rubber the way a solvent-based product would.
How is this different from the slow-leak process for a standard tire?
A standard slow leak usually means checking the tread and bead. A TPMS wheel adds the valve core, stem base, and sensor grommet as separate possible leak points, so the spray-and-check process runs through more spots before landing on the answer.
If TPMS comebacks are eating tech time, we're glad to talk through how shops are running this in their bays. Reach us at sales@chaosmoto.com or 480-829-7888.
