The 9 Best AC Leak Stoppers
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
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.