Updated February 10, 2021 by Kaivaan Kermani

The 9 Best AC Leak Stoppers

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This wiki has been updated 17 times since it was first published in June of 2016. Calling out an appliance repair person is expensive, so it may behoove you to try one of these AC leak stoppers first if your unit is giving you problems. They can deliver an instant and economical fix for many car and household air conditioning issues. Just be sure you know what you're doing before trying to use any of these, however, as escaping refrigerant can be hazardous to your health. When users buy our independently chosen editorial recommendations, we may earn commissions to help fund the Wiki.

1. RectorSeal Magic Frost

2. Leak Saver Direct Inject

3. Nu-Calgon EasySeal Ultimate

Editor's Notes

February 09, 2021:

Depending on the circumstance, you may need to pump down your condenser to add these sealants as they will move with your refrigerant and fill in the gaps, though this won’t always be the case. For instance, the Nu-Calgon EasySeal Ultimate and RectorSeal Magic Frost won’t require pumping down and letting the system stand before recharging. You’ll obviously need a method to add the refrigerant for direct-inject systems, which is why I’ve included the convenient leak shot HVAC which you can apply to the low side service port of your system without having to charge it in with refrigerant.

May 20, 2019:

Not every option listed here is suitable for both home and auto use, so make sure to double-check that whichever one you're considering is suitable for your intended application before buying. Likewise, while most are universally compatible with refrigerants and oils, that's something you should be absolutely certain of before installation.

The method of installation should also be carefully considered. Some can screw directly into your system, while others require a connection hose (which may or may not be provided — Red Tek ProSeal22 requires you to supply your own, for example).

Beyond that, there are a variety of features that you should think about. One important consideration is whether you want the sealant to mix with the oil; the advantage to this is that it's certain to form a seal, while the danger is that it might solidify prematurely, causing a clog that derails your whole system. Nu-Calgon A/C Easy Seal is one of the few that doesn't mix with the oil, if that's your preference.

Special Honors

Leak Shot HVAC The Leak Shot HVAC makes using direct-injection AC leak stoppers relatively easy and circumvents the need of having to use an RRR machine. It comes with 3 refrigerant-grade CO2 cartridges which can each last for 5 to 8 injections, as well as 3/4” and 1/2” rubber condensate line adapters, and a flexible extension hose. leaksavers.com

4. Leak Saver Ultimate

5. Red Tek ProSeal22

6. Cliplight Super Seal Advanced 944KIT

7. AC Leak Freeze 00284

8. Interdynamics AC PRO MRL-3

9. ZeroR Kit


Kaivaan Kermani
Last updated on February 10, 2021 by Kaivaan Kermani

Kaivaan grew up in a little town called York in the north of England, though he was whisked off to sunny Jamaica at the age of 14, where he attended high school. After graduating, he returned to the UK to study electronic engineering at the University of Warwick, where he became the chief editor for the engineering society’s flagship magazine. A couple of uninspiring internships in engineering later however, and after some time spent soul-searching and traveling across Asia and East Africa, he he now lives and works in in Dubai.


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