Best Radiator Stop Leak Products in 2023 (Review & Buying Guide)

Sometimes it might be quite difficult to find the best radiator stop leak products. 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 stop leak products buying guide.

We Recommend:

#PreviewProduct
1 Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz. Bar's Leaks PLT11 Pelletized HD Radiator Stop Leak - 11 oz.
2 Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams
3 Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz , Gray Bar's Leaks 1186 Liquid Aluminum Stop Leak - 16.9 oz , Gray
4 Bar's Leaks Radiator Stop Leak 2X Concentrate, 6 oz. Bar's Leaks Radiator Stop Leak 2X Concentrate, 6 oz.
5 Bar's Leaks 1196 Radiator Stop Leak - 11 oz. , Grey Bar's Leaks 1196 Radiator Stop Leak - 11 oz. , Grey
6 Bar's Leaks Cooling System Radiator Stop Leak 16.9 oz. Bar's Leaks Cooling System Radiator Stop Leak 16.9 oz.
7 Liqui Moly 20132 Radiator Stop Leak, 0.25 l, 1 Pack Liqui Moly 20132 Radiator Stop Leak, 0.25 l, 1 Pack
8 Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz. Bar's Leaks 1109 Block Seal Liquid Copper Intake and Radiator Stop Leak - 18 oz.
9 PRESTONE PRODUCTS CORP Prestone Products AS145Y Radiator Stop Leak, 11-oz. - Quantity 6 PRESTONE PRODUCTS CORP Prestone Products AS145Y Radiator Stop Leak, 11-oz. - Quantity 6
10 Niteo Motor Medic C312 Radiator Sealer and Stop Leak - 11 oz. Niteo Motor Medic C312 Radiator Sealer and Stop Leak - 11 oz.
11 Koehler Enterprises KE28BX 10 Piece Hose Clamp Box (Size SAE 28) , silver Koehler Enterprises KE28BX 10 Piece Hose Clamp Box (Size SAE 28) , silver
12 K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair , BLUE K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair , BLUE
13 ACDelco GM Original Equipment 10-108 Cooling System Sealing Tabs - 4 g (Pack of 5) ACDelco GM Original Equipment 10-108 Cooling System Sealing Tabs - 4 g (Pack of 5)
14 Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz, 1 Pack Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz, 1 Pack
15 AlumAseal ASLC16 Radiator Stop Leak and Conditioner Liquid - 16 Fl oz. AlumAseal ASLC16 Radiator Stop Leak and Conditioner Liquid - 16 Fl oz.
16 Red Angel 49496 A/C Stop Leak - 2 Ounce Red Angel 49496 A/C Stop Leak - 2 Ounce
17 C and R Racing Radiators 59-00001 Dike Stop Leak, 1 Pack C and R Racing Radiators 59-00001 Dike Stop Leak, 1 Pack
18 Bar's Leaks J-100 DiFM Cooling System Treatment - 5 Grams, Tan Bar's Leaks J-100 DiFM Cooling System Treatment - 5 Grams, Tan
19 Genuine GM (12378255) Fluid 3634621 Cooling System Seal Tablet - 4 Grams, (Pack of 5) Genuine GM (12378255) Fluid 3634621 Cooling System Seal Tablet - 4 Grams, (Pack of 5)
20 Bar's Leaks High Mileage Cooling System Repair, 16.9 oz Bar's Leaks High Mileage Cooling System Repair, 16.9 oz

Our Favorite Radiator Stop Leak Products Reviews:

SaleBestseller No. 1
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
SaleBestseller No. 2
Bar's Leaks HDC Radiator Stop Leak Tablet - 60 Grams
  • Seals leaks
  • Conditions cooling system
  • Inhibits rust and corrosion
  • Lubricates water pump seals
  • Helps control electrolysis
SaleBestseller No. 3
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
Bestseller No. 4
Bar's Leaks Radiator Stop Leak 2X Concentrate, 6 oz.
  • Product type :Auto Accessory Stops and seals coolant leaks
  • Package dimensions :4.064 cm L x6.096 cm W x12.446 cm H It has double the power of most other stop leak products and saves
  • country of origin :United States coolant and/or water. One bottle treats systems
  • package weight :0.81lbs Works with all types and colors of antifreeze That’s why we created the Bar’s Leaks Radiator Stop Leak 2X Concentrate.
  • Seals Leaks in Radiators, Gaskets, Heater Core & Freeze P lugs Works with all types and colors of antifreeze coolant
SaleBestseller No. 5
Bar's Leaks 1196 Radiator Stop Leak - 11 oz. , Grey
  • Works with all types and colors of anti-freeze coolant
  • Stops and seals coolant leaks
  • One bottle treats up to 4 gallons
  • Works with all types and colors of anti-freeze coolant
  • Stops and seals coolant leaks
Bestseller No. 7
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
Bestseller No. 8
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
Bestseller No. 10
Niteo Motor Medic C312 Radiator Sealer and Stop Leak - 11 oz.
  • MOTOR MEDIC is a local family owned company based out of Charlotte, NC. For more than 75 years, LIQUID WRENCH products, developed by the people who use them, has earned the trust of hard-working tradesment and the active DIYer through consistent, superior performance and a commitment to innovation.MOTOR MEDIC
Bestseller No. 11
Koehler Enterprises KE28BX 10 Piece Hose Clamp Box (Size SAE 28) , silver
  • 300 series stainless steel band provides maximum corrosion resistance to salt and most chemicals
  • SAE size 28, clamping range from 1 - 1/4 inches to 2 -1/4 inches (3,33 to 5,72 cm)
  • Ideal for automotive, home maintenance, plumbing, industrial and marine applications
  • Suitable for virtually any clamping application
  • Versatile and easy to use and maintain
SaleBestseller No. 12
K-Seal ST5501 Multi Purpose One Step Permanent Coolant Leak Repair , BLUE
  • Permanent Coolant Leak Repair - Just Shake, Pour And Go.Fit Type: Universal
  • 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
Bestseller No. 13
ACDelco GM Original Equipment 10-108 Cooling System Sealing Tabs - 4 g (Pack of 5)
  • Engineered for use on a variety of engine components - effective on: oil pan, ladder frame, front and rear covers, t-joints, manifold corners, intake, manifold end seals, and cam covers
  • Designed for quick and easy application, assembly may be filled with oil or coolant immediately after applying sealant and torqueing the bolts
  • High viscosity product that cures when exposed to air
Bestseller No. 14
Prestone AS145 Stop Leak Repair for Radiators, Heater Cores, and Hoses, 11 oz, 1 Pack
  • Patented formula quickly stops leaks in radiators, water pumps, and heater cores
  • Boosts corrosion inhibitors to protect against pitting and corrosion, which cause radiator leaks
  • Combination of natural and synthetic components provides the ability to seal leaks up to 0.020" x 0.5"
  • Seals even large leaks without interfering with the flow through the radiator or heater core
  • Stops the leak as well as the corrosive condition that causes it
Bestseller No. 15
AlumAseal ASLC16 Radiator Stop Leak and Conditioner Liquid - 16 Fl oz.
  • Stops leaks safely, quickly and easily
  • Compatible with all antifreeze and coolants
  • Safe and effective for all metal, plastic and rubber cooling system parts
  • Lubricates water pump
  • Guaranteed to work
SaleBestseller No. 16
Red Angel 49496 A/C Stop Leak - 2 Ounce
  • Remarkable ability to repair and seal leaks in condensers, evaporators, connection hoses, gaskets, and O-rings
  • Contains no solid or particulate matter that will clog the A/C system, or harm a recovery unit
  • Forms a chemical weld sealing leaks in both R-12 or R-134a systems
  • Safe to use and best of all — it’s a permanent seal
  • Guaranteed
Bestseller No. 17
C and R Racing Radiators 59-00001 Dike Stop Leak, 1 Pack
  • Can prevent a DNF in the event of a radiator puncture, cracked cylinder head, or head gasket Problem
  • After extensive research, C & R racing has found a stop leak that doesn't leave a residue
  • C&R Stop Leak stays suspended in the water so that when the water is drained, all of the stop leak is drained with the water leaving no residue
  • Package Weight : 1.2 pounds
SaleBestseller No. 18
Bar's Leaks J-100 DiFM Cooling System Treatment - 5 Grams, Tan
  • Seals internal, external and coolant to oil leaks
  • Stops radiator tank seal leaks
  • Inhibits the formation of rust and scale
  • Helps control electrolysis and helps neutralize pH imbalance
  • Lubricates water pump seal
Bestseller No. 19
Genuine GM (12378255) Fluid 3634621 Cooling System Seal Tablet - 4 Grams, (Pack of 5)
  • Non-toxic
  • DEX-COOL compatible
  • Engine application is based on liters of volume in cooling system
  • Formulated for automotive use
  • For use with all vehicles
SaleBestseller No. 20
Bar's Leaks High Mileage Cooling System Repair, 16.9 oz
  • Stops Cooling System Leaks
  • Compatible with all brands of anti-freeze including conventional green or blue and extended life red/orange or yellow (OAT/HOAT) coolant
  • Premium Carbon Fiber Formulation For Extended Protection
  • Country Of Manufacture: United States

Last update on 2023-01-12 / Affiliate links / Images from Amazon Product Advertising API

How to find the best radiator stop leak products?

Here, we’ll be going over a number of factors that you can use to ensure that you’re purchasing the best radiator stop leak products 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 stop leak products 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 stop leak products 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 stop leak products to find what you’re looking for:

Brand

In some cases, the brand of radiator stop leak products 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 stop leak products 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 stop leak products 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 stop leak products 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 stop leak products 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.