If you’re dealing with a leaking air conditioning system in your car, you might be tempted to grab a can of AC leak-sealer from the nearest auto parts store. After all, it’s an easy fix, right? But before you go down that road, there are some important things you should know about these products and how they might affect your vehicle in the long run.
Two of the most common questions we hear from our customers are:
- Can AC leak-sealer damage my car’s AC system by gumming it up?
- Is it true that most shops won’t service a car’s AC system if it contains leak-sealer because it could damage their equipment?
These are valid concerns, and the answers might surprise you.
What Happens When You Use AC Leak-Sealer?
Imagine this scenario: Your car’s AC isn’t working because of a bad leak on the manifold line and the O-ring leading to the compressor. You’re planning a long road trip, and with summer in full swing, you can’t afford to be without air conditioning. You head to the auto parts store and pick up a can of R-134A refrigerant that also contains oil and leak-sealer. The clerk reassures you that the sealer is minimal and poses no risk—after all, they recommend it to customers and use it themselves.
But here’s the thing: just because it’s easy doesn’t mean it’s the best solution. While the idea of a quick fix is appealing, the reality of using an AC leak-sealer can be far more problematic.
Will AC Leak-Sealer Destroy My AC System?
The short answer? It’s possible.
AC leak-sealers are designed to plug small leaks by reacting with moisture and air at the site of the leak, forming a seal. However, this process doesn’t always go as planned. If your AC system has a significant leak, the sealer may not work at all. And even if it does, the fix is often temporary.
Over time, the sealer can start to clog other parts of the AC system, such as the condenser, evaporator, or compressor. This can lead to bigger issues down the line, requiring expensive repairs or even a complete system replacement.
A good rule of thumb: If your AC system can’t hold a vacuum for 45 minutes during testing, no amount of sealer is going to save it. It’s better to repair the leak properly than to risk further damage by using a stop-gap solution.
Will Shops Refuse to Service an AC System with Leak-Sealer?
This is where things get tricky. Many repair shops, including ours, will not service an AC system that has been treated with leak-sealer. Why? Because when the sealer runs through our equipment during the evacuation process, it can contaminate and potentially ruin our expensive machines.
If our AC recovery machine gets clogged with sealer, it can be costly to repair or replace. That’s why many shops, including ours, take a hard pass on working with systems that have been treated with these products.
The Bottom Line: Fix It Right the First Time
When it comes to your car’s air conditioning system, shortcuts can lead to costly consequences. If you’re dealing with a leak, the best course of action is to have it repaired by a certified AC technician. They can properly diagnose the issue, replace faulty components like hoses and O-rings, and recharge the system to ensure it’s working efficiently.
Our recommendation? Skip the stop-leak products altogether. Whether it’s for your AC, power steering, or even tires, temporary fixes like these are rarely worth the risk. Instead, invest in a proper repair that will save you money and headaches in the long run.
What You Can Do
If you’re handy and comfortable with basic car repairs, you might consider doing some of the work yourself. For instance, if the issue is with a hose and O-ring, you could
replace those parts on your own and then bring the car to a professional for a system vacuum and recharge. This way, you’re ensuring the problem is fixed correctly without introducing harmful sealers into the system.
However, if you’re not confident in your skills, or if the problem is more complex, it’s always best to leave it to the professionals. A certified technician has the tools and expertise to handle the job without causing further damage to your vehicle.
Final Thoughts: When It Comes to AC Repairs, Skip the Quick Fixes
AC leak-sealers might seem like a convenient solution to a frustrating problem, but they often do more harm than good. Rather than risking damage to your AC system—and potentially voiding any future service options at your local shop—take the time to have your AC repaired correctly. In the long run, this approach will save you time, money, and stress, ensuring your car stays cool and comfortable during those long summer drives.
If you have any questions or need professional advice, don’t hesitate to reach out to us. We’re here to help you keep your car in top shape—without the risks that come with quick fixes.
