Best Radiator Sealant in 2022 (Review & Buying Guide)

Sometimes it might be quite difficult to find the best radiator sealant. With every niche market offering so many different products, it makes sense that this is the case.

Unfortunately, this very fact can make it incredibly difficult to find the item that best suits your needs, which is why we’ve put together this radiator sealant buying guide.

Our 10 Favorites:

Our Favorite Radiator Sealant Reviews:

SaleBestseller No. 1
Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz , Gray
  • Bar's Leaks Liquid Aluminum Stop Leak seals radiator leaks. Seals freeze plug leaks. Repairs gasket leaks and heater core leaks. Lowers water temperature.
  • Seals radiator leaks
  • Seals freeze plug leaks
  • Repairs gasket leaks
  • Special Shipping Information: This item cannot be returned and has additional shipping restrictions
SaleBestseller No. 2
K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair, Blue
  • Permanent Coolant Leak Repair - Just Shake, Pour And Go
  • Mixes With All Antifreeze
  • No Draining Or Flushing
  • Fixes Cracks And Leaks In Radiator, Head Gasket, Freeze Plugs, Cylinder Heads, Heater Core, Water Pump Casing And Engine Blocks
SaleBestseller No. 3
Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz.
  • Seals larger leaks seals
  • Repairs heater core leaks
  • Repairs freeze plug leaks
  • Repairs blown head gaskets
  • Repairs blocks
SaleBestseller No. 4
Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz.
  • Seals leaks
  • Conditions cooling system
  • Inhibits rust and corrosion
  • Lubricates water pump seals
  • Helps control electrolysis
Bestseller No. 5
Sherco-Auto K-Seal Multi Purpose One Step Permanent Coolant Leak Repair 8 oz Gasket Radiator
  • Sold as (1) 8 0z. Bottle
  • Permanent coolant leak repair - Just shake, pour and go. Mixes with all antifreeze. No draining or flushing.
  • Fixes cracks and leaks in radiator, head gasket, freeze plugs, cylinder heads, heater core, water pump casing and engine blocks
  • The Safe and Easy Way to Fix a Coolant Leak. Works also a Radiator stop leak, head gasket stop leak and engine stop leak.
  • Permanent Coolant Leak Repair with K-Seal
Bestseller No. 7
J-B Weld 2120 Radiator and Plastic Repair Kit
  • RADIATORWELD: Our radiator and plastic tank repair kit has all you need for making professional quality, permanent repairs with state of the art components and easy to follow instructions.
  • COUNT ON US: For more than 40 years, our products have earned a loyal following from people who take pride in their work. With each product we innovate, we continue to provide the world's strongest bond for your projects.
  • SIMPLE TO USE: No removal of tank or radiator is required to stop leaks. Easily fix holes up to 3/8" diam. or cracks up to 4" long. Includes epoxy putty, fiberglass cloth, sandpaper, and applicator.
  • VERSATILE & DEPENDABLE: Great for radiators, washer fluid tanks, storage tanks, water tanks, plastics, composites, PVC and more. Professionals, mechanics and avid DIYers know J-B gets the job done.
  • NO PROJECT TOO BIG OR TOO SMALL: We have all the products you need to get the job done right. JB Weld always delivers the legendary performance of the World's Strongest Bond.
Bestseller No. 8
Permatex 09116 Fuel Tank and Radiator Repair Kit
  • Seals holes, seams, or cracks on metal tanks, radiators, or gas cans
  • Quickly and easily knead together the two-component stick to form a tight seal
  • Provides excellent chemical and moisture resistance
  • Cures within 2 hours at ideal temperature
  • Not recommended for use on plastic gas tanks
Bestseller No. 9
Super Glue Pro Seal N62020 Instant Gas Tank and Radiator Repair
  • Instant Gas Tank and Radiator Repair
  • 0.7-Ounce strip
  • Easy to use putty
  • Permanently seals cracks and split seams
  • Hardens like steel
SaleBestseller No. 10
Liqui Moly 20132 Radiator Stop Leak, 0.25 l, 1 Pack
  • LIQUI MOLY Radiator Stop-Leak completely seals such leaks immediately with ease. 
  • Secures the combustion chamber from damages caused by coolant admission
  • For all cooling water and heating systems with and without water filters

Last update on 2022-10-01 / Affiliate links / Images from Amazon Product Advertising API

How to find the best radiator sealant?

Here, we’ll be going over a number of factors that you can use to ensure that you’re purchasing the best radiator sealant for you.

Regardless of which type of item you’re looking to buy, chances are that there are existing buying guides on the internet, all of which aim to give you good radiator sealant recommendations.

Despite these recommendations, however, it’s always a good idea to do your own research. In addition to this research, asking yourself the following questions is also super helpful:

  • What features does the radiator sealant need to have to be perfect for my needs?
  • What is my budget?
  • Do I need to purchase a certain brand?

Once you’ve answered these questions and have a good idea of what you’re looking for and the buying process becomes much easier. Keep in mind that when looking for the best product, there’s no need to rush. In fact, very rarely are the ideal products found by choosing the first one you see or by basing your decisions on only one factor. Take your time and enjoy the process!

Now, with the answers to the previous questions in mind, we urge you to use our upcoming buying guide for radiator sealant to find what you’re looking for:

Brand

In some cases, the brand of radiator sealant is very important. For example, if you’re looking for an item that works in tandem with another, you might very well need both products to be the same brand. If this is the case, it’s vital to pay attention to this factor, as choosing the wrong product can mean the difference between wasting your money and buying a great product that functions as it should.

Features

The features in any given radiator sealant are important because they can dictate which version of an item you need and how much money you need to spend. Consider all the key features that you want your item to have and don’t settle for anything that doesn’t check at least ¾ of your boxes.

Reviews

Customer reviews about radiator sealant are crucial – especially when you’re buying a product that costs a lot of money or serves a big importance. Luckily, most products can be found online, which means that it’s common for there to be scores of customer reviews from those who have already purchased any given product.

Pay attention to these reviews. Take note of the pros and cons that they mention, and factor these into your big decision. In some cases, you’ll be forced to sacrifice one con in order to gain a particular pro, but being aware of the potential con is going to be beneficial in either case.

Quality

Of course, quality is key. You don’t want to purchase a low-quality product. If you do, you run the risk of your item breaking, not working properly, or otherwise proving to be very disappointing, as well as a waste of money.

You can compare radiator sealant quality by researching what your potential purchases are made from, contrasting the individual items against each other to discern which one is made of the best materials.

Warranty

Warranty isn’t always going to be important, but it definitely can be. This is especially true if the item in question is tech-related or expensive. A good warranty will be valid for an extended time after purchase and cover a variety of problems ranging from item defects to random accidents, water damage, and other miscellaneous events that could ruin your product.

Conclusion

The quest to find the best radiator sealant can be daunting – but it doesn’t have to be. It can be made much easier by asking yourself a few simple questions and then thinking critically about the items you want to buy. Consider their features, quality, brand, warranty, and customer reviews and you’re more likely to make a great purchase.