How Does Ac Leak Sealer Work?

You have two options – melt your way to a heat-stroke or get your aircon fixed with a ton of money. What do you choose? In an ideal setup, you’d be taking care of that leak yourself.

But inconveniences don’t come with a warning tag. And on a hot summer day, a leak in the AC is a little more than “just an inconvenience.” Using an AC leak sealant is a cost-effective way to deal with the situation.

So, if you’re wondering how does ac leak sealer work, we’ve got the answers right here. By the end of this article, you’ll see what the hype is all about. Take things into your own hands and find out how these sealants work!

Let’s get to it.

How Does Ac Leak Sealer Work?

The AC leak sealants have been the best-kept secret of many natural gas companies globally. They’ve been using it to fix small damages in gas pipelines for decades. But now that the cat’s out of the bag, it’s time for us regular folks to have some fun.

Imagine an egg turning solid on high heat. That’s basically how this works too. But the difference here is that the sealant liquid reacts to the temperature of the leaked spot – not a stove. (And you obviously can’t eat it)

Here are the details of this process –

Pump it Down!

If you’re working on a system with a low side pressure, you’ll need to pump it down first. Lower it down from 65 psi to around 40 or 50 psi. After this, you can inject the liquid after shaking the can well.

Injecting Methods

You’ll need to inject the sealant into the system for it to activate. Mechanics typically get this done by using stick capsules, plastic syringes, and direct injection. If you’re working with a high-pressure system, then the best option, in our opinion, is using multi-dose disposable cartridges.

Travel Time

When the liquid is released into a leaking system, it travels through it as a drink goes through a straw when sipped. It takes around one or two minutes for it to enter the pipe or unit fully. But it takes longer to start activating.

It starts to form a web-like seal at the spot where there is a temperature difference or pressure change. Sometimes this process takes around 4 minutes to begin. So you’ll have to sit tight and wait.

Some of the car aircon takes longer to activate the sealant. It usually ranges from 10 minutes to half an hour for longer pipes or bigger units.


This can occur in three different ways depending on what sealing product you’re using. If it’s those grain-based ones, it’s going to plug the leak. And for the ones reacting to moisture, you’ll see them harden.

The temperature difference in a leaked area causes condensation to form, and that triggers the solution. Unlike the case with traditional leak detectors, you don’t have to wait for hours to find micro leaks with this.

The liquid automatically detects minuscule corrosions, damages, and loose fittings. Having done so, it easily repairs them on its own.

As we said before, this is a homogenous solution. And when it comes in contact with temperature change, the paraffinic portion falls out of the solution. The result is that you get to see it magically collecting on the leaked site – ending your local mechanic’s whole career.


So, your sealant has been successfully inserted. Now what? The next step is to charge the system to achieve the correct system pressure. Because no matter how good your installation skills are, this isn’t going to work when your unit itself has pressure issues.

Remember to be careful and not overcharge. The optimum pressure and temperature are needed for the liquid to get activated in all the right places.

Full Circulation

For the product to completely seal all the leaks throughout the unit, run it for an hour or so. This will ensure full circulation, and you’ll get the best results.

Types of AC Sealers

You’ll notice people getting either of the two types of sealants – chemical ones or powder ones. And while both work quite well, there are a few differences you should be aware of –

Chemical-Based AC Sealers

Ask any HVAC technician, and they’ll say this is the only sealant you’d better be using. Not only are these the safest type out there, but they’re also least likely to cause unit damage.

The reason for their popularity is due to the mechanism. These sorts of sealants work by creating a permanent patch over the leak. It doesn’t seal like a concrete block but works like a welding chemical inside.

If this is your first time dealing with a pesky leak yourself, we recommend using one of these. They’re easier to install and comparatively cheap.

Powder-Based AC Sealers

You’re not going to find these types often nowadays. They’re the predecessor of the chemical sealers, and they work by plugging the leak. Just as the name suggests, these are made of powder particles.

These work ideally with non-pressurized systems. But here’s the catch – most AC units of today are pressurized.

So you can’t really use them anymore without risking clogs and further damage. Since they sit in the refrigerant line, they may clog it instead of fixing the leak.

Tips on Using AC Sealers

  • A basic rule of thumb is to check the instructions and directions first. Since these are chemicals you’re dealing with, you better be careful and not neglect the fine text.
  • Another tip we can offer is to check the tonnage it can handle before making the purchase. Don’t go setting yourself up for failure with a sealant that’ll be too weak to handle the tonnage.
  • You’ll also want to consider your system type. Are you looking to fix your car’s aircon? Is the leak in an HVAC system? Trust us – you don’t want to use the wrong product for the wrong system.
  • And finally, make sure the sealing liquid you’re getting is compatible with the oil and refrigerant in your unit. Some of these are for metal parts, and others are for rubber.

Any Risks Involved?

Leaking in any unit works both ways. What we mean is, just as your AC’s refrigerant is going out, moisture and condensation are going in. This is why sealers are made to react to either moisture or temperature and pressure changes.

Can you guess what the risk involved here is? Well, water doesn’t stay in one place, and it can be present in important parts like the condenser or valves.

If the sealant hardens there, it’s game over!

Your AC may actually stop functioning altogether if this happens. This is why we highly suggest getting the products that are pressure-reacting and not moisture sensitive.

Final Words

Who doesn’t love someone who knows how to fix things?

Now you can show off to your friends and neighbors when they need help with their ACs. Go on and flex your knowledge the next time someone asks – how does ac leak sealer work. Getting on the popular book has never been this easy.

Go on and give those over-priced servicing centers and mechanics a good run for their money. Thank us later!

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