- Product
- Aerosure AC Leak Detector 500 mL
- Shows
- Bubbles at the leak
- Check
- Flare nuts, joints, U-bends
- Then
- Repair, re-test, recharge
Where leaks usually are
| Location | Why it leaks |
|---|---|
| Flare nuts at indoor and outdoor units | Poor flaring or over- or under-tightening |
| Brazed joints | Porous or cracked brazing |
| Service valves | Worn valve cores and caps left off |
| Coil U-bends and return bends | Vibration, corrosion and pinholes |
How to run a bubble test
- Make sure the system is under pressure.
- Clean the joint so old dirt does not hide bubbles.
- Spray Aerosure AC Leak Detector evenly on the joint.
- Watch for a minute. Small, growing bubbles or foam mark the leak.
- Wipe the area after the test.
Pinholes in the indoor coil
Tiny leaks across the coil itself can be formicary corrosion. See our guide to formicary corrosion.
Products used
Quick answers
How do you find a small AC gas leak?
Pressurise the system and spray a leak detection solution such as Aerosure AC Leak Detector on each joint. A leak forms growing bubbles. Check flare nuts, brazed joints, valves and U-bends first.
Where do AC gas leaks usually happen?
Most leaks are at flare nuts, brazed joints, service valves and coil U-bends. Thin copper in indoor coils can also leak through formicary (pinhole) corrosion.
Should I recharge gas without finding the leak?
No. Find and fix the leak first, then pull a vacuum and recharge to the maker’s specification. Topping up a leaking system wastes gas and the AC loses cooling again.