The 5 Best Radiator Stop Leaks For 2018 – Reviews & Analysis

Car overheating is a common problem I often face. One to blame is a malfunction in the radiator. Of course, most of us who own a car know that the radiator is not immune to damage as leaks may come out.

That’s when I realized the importance of a radiator stop leak. It basically acts as a first aid in cases when a car repair shop is inaccessible.

However, choosing a random product is not a practical choice. This is why I want to share with you some of the most trusted brands you can use for your radiators. Let me introduce to you the best radiator stop leak on the market I have in mind.

Car overheating is a common problem I often face. One to blame is a malfunction in the radiator. Of course, most of us who own a car know that the radiator is not immune to damage as leaks may come out. 


That’s when I realized the importance of a radiator stop leak. It basically acts as a first aid in cases when a car repair shop is inaccessible.

Top Picks Of 5 Best Radiator Stop Leak 2018 Reviews

However, choosing a random product is not a practical choice. This is why I want to share with you some of the most trusted brands you can use for your radiators. Let me introduce to you the best radiator stop leaks I have in mind.

1. Genuine GM Fluid 3634621 Cooling System Seal Tablet

These non-toxic Genuine GM Fluid Cooling System Seal Tablets are in popular demand by users as they are DEX-COOL compatible. They are also travel-friendly since they don’t come in large bottles. Convenience is a guarantee.

The length of time it takes for it to take effect is also proven. After crushing the tablets and adding them to the cooling system, tiny leaks are already covered up to keep the system functioning well again.

These non-toxic Genuine GM Fluid Cooling System Seal Tablets are in popular demand by users as they are DEX-COOL compatible. They are also travel-friendly since they don’t come in large bottles. Convenience is a guarantee.

The length of time it takes for it to take effect is also proven. After crushing the tablets and adding them to the cooling system, tiny leaks are already covered up to keep the system functioning well again.

Genuine GM Fluid 3634621 Cooling System Seal Tablet

Check More Photos and Price at: amazon.com

The Genuine Gm Fluid Cooling System Seal Tablets works for all kinds of vehicles. Since it works for all, you can purchase more than a pack for reserve without worrying if the product suits the automobile you are driving or not.

The Genuine Gm Fluid Cooling System Seal Tablets works for all kinds of vehicles. Since it works for all, you can purchase more than a pack for reserve without worrying if the product suits the automobile you are driving or not.

2. Prestone AF888 Dex-Cool Antifreeze

Prestone Dex-Cool Antifreeze is made to provide protection to your radiator up to 5 years, or after running about 150,000 miles! Due to the product’s performance, the need to keep on purchasing radiator stop leaks can be minimized, thus allowing you to save an amount of money while protecting your car from damage at the same time.

Light-duty trucks will benefit best from this product. It protects the engine from corrosion, and extreme temperature is now off your list of worries as well since the Prestone Antifreeze will protect your radiator from such extremes.

Light-duty trucks will benefit best from this product. It protects the engine from corrosion, and extreme temperature is now off your list of worries as well since the Prestone Antifreeze will protect your radiator from such extremes.

Prestone AF888 Dex-Cool Antifreeze

Check More Photos and Price at: amazon.com

Because of its blend of premium, long-lasting inhibitors, Prestone Dex-Cool Antifreeze will truly help you bother less about the damage your radiator can get. Its performance is trusted and reliable as time passes by.

Because of its blend of premium, long-lasting inhibitors, Prestone Dex-Cool Antifreeze will truly help you bother less about the damage your radiator can get. Its performance is trusted and reliable as time passes by.

3. AlumAseal ASBPI12-12PK Radiator Sealer Blister Card

Another product that is designed for cars of various makes and brands is the AlumaSeal Radiator Sealer Blister Card. Once the leak starts, the product safely stops it and prevents the cooling system from clogging.

The powder solution is safe to be combined with all types of antifreeze and lubricates the water pump. Once applied to the radiator, it seals any present leaks so that you can hit the road once again.

Another product that is designed for cars of various makes and brands is the AlumaSeal Radiator Sealer Blister Card. Once the leak starts, the product safely stops it and prevents the cooling system from clogging.


The powder solution is safe to be combined with all types of antifreeze and lubricates the water pump. Once applied to the radiator, it seals any present leaks so that you can hit the road once again.

AlumAseal ASBPI12-12PK Radiator Sealer Blister Card

Check More Photos and Price at: amazon.com

AlumAseal Radiator Sealer Blister Card is yet another handy product that you can keep in your car yet does not consume much of your space. Little in size, big in benefits!

AlumAseal Radiator Sealer Blister Card is yet another handy product that you can keep in your car yet does not consume much of your space. Little in size, big in benefits!

4. K-Seal ST5516 HD Multi Purpose One Step Permanent Coolant Leak Repair

Just like every other radiator stop leak in the market, the K-Seal HD Multi-Purpose Permanent Coolant Leak Repair does its job in fixing cracks and leaks in the radiator and other engine parts. Moreover, it can even mix with all kinds of antifreeze.

Vehicles with larger engine capacities will find this product to be a perfect match. With a simple shake, your engine will immediately resume its job, and you’ll be back on the road with a leak-free radiator.

Just like every other radiator stop leak in the market, the K-Seal HD Multi-Purpose Permanent Coolant Leak Repair does its job in fixing cracks and leaks in the radiator and other engine parts. Moreover, it can even mix with all kinds of antifreeze.


Vehicles with larger engine capacities will find this product to be a perfect match. With a simple shake, your engine will immediately resume its job, and you’ll be back on the road with a leak-free radiator.

K-Seal ST5516 HD Multi Purpose One Step Permanent Coolant Leak Repair

Check More Photos and Price at: amazon.com

The K-Seal HD Multi-Purpose Permanent Coolant Leak Repair contains ceramic microfibers and copper particles that do the part of finding the cracks and holes in your leaking radiator. It also guarantees you safety and frees you from the hassles of worrying whether you need to pay your engines another visit or not.

The K-Seal HD Multi-Purpose Permanent Coolant Leak Repair contains ceramic microfibers and copper particles that do the part of finding the cracks and holes in your leaking radiator. It also guarantees you safety and frees you from the hassles of worrying whether you need to pay your engines another visit or not.

5. Bar's Leaks 1150 Grey Cooling System Repair

Bar's Leaks Cooling System Repair works twice as better as some of the other products as it reduces antifreeze loss alongside the task of finding and sealing leaks. It is also compatible with all brands of anti-freeze, leaving you fewer problems in fixing up your engine.

Perhaps the best part about this product is that it contains premium carbon fiber formulation to further protect the engines, along with Xtreme Cool to hinder overheating and lower water temperature in the engine.

Bar's Leaks Cooling System Repair works twice as better as some of the other products as it reduces antifreeze loss alongside the task of finding and sealing leaks. It is also compatible with all brands of anti-freeze, leaving you fewer problems in fixing up your engine.


Perhaps the best part about this product is that it contains premium carbon fiber formulation to further protect the engines, along with Xtreme Cool to hinder overheating and lower water temperature in the engine.

Bar's Leaks 1150 Grey Cooling System Repair

Check More Photos and Price at: amazon.com

With Bar's Leaks Cooling System Repair, there is no need to drain your cooling system after use as it stays to protect the engine from more cases of overheating and leaks. This is a wise choice as it is practical and effective.

With Bar's Leaks Cooling System Repair, there is no need to drain your cooling system after use as it stays to protect the engine from more cases of overheating and leaks. This is a wise choice as it is practical and effective.

How To Choose Perfect Radiator Stop Leaks

After having been acquainted with some of the top-performing products in the market, there are some factors we have to consider before purchasing the best product for our vehicles. These are as follows:

Leak Source

The light indicating that the coolant is running low is a fair warning to check on the engines. However, there are some leaks that are not visible. Radiator stop leaks like Genuine GM Fluid Cooling System Seal Tablets work best in stopping the leaks from adding up. They serve as stoppers for leaks that have just begun and stop further leaks from coming out.

Leak Size

The amount of fluid seeping out from the radiator can be one indicator of how much leakage is occurring in the engines. There are products that work best for small leaks, and some work best for larger ones.

Genuine GM Fluid Cooling System Seal Tablets and AlumAseal Radiator Sealer Blister Card are best for dealing with small leaks that have just started to surface. However, we must not wait for leaks to go big.

Once the leaks start, they need to be attended to right away to prevent further expenses of fixing larger leaks.

Material used for the radiator​

Various radiators are made from different materials. Some are made of aluminum, cast iron, mild steel, or stainless steel. There are some products that work best for a specific radiator material such as the AlumAseal Radiator Sealer Blister Card which performs at its best when handling a leaking radiator made of aluminum.

Some products may contain chemicals that don’t work quite well with the radiator due to its composition. This is one important factor you need to look out for.

Engine capacity

Some products are made to mend radiators best according to their capacity.

Products like Prestone Dex-Cool Antifreeze are meant for light-duty trucks, while products such as the K-Seal HD Multi-Purpose Permanent Coolant Leak Repair work best for heavy-duty engines.

It is best to determine which product fits the vehicle best based on the capacity of the engine to ensure the product’s effectivitness as well.

How to Use Radiator Stop Leaks

Generally speaking, before diving into the product, you should first take care of your car. Make sure the engine is already off and has cooled down.

Control your vehicle’s heater, then pour the product into the radiator and add coolant to appropriate levels when needed. Seal the radiator once again and start hitting the road and let the product seal leaks. This can only be made possible with the vehicle running.

Each product is uniquely manufactured, hence it’s best to carefully take note of how each package should be handled. Some products come in powders, and they need a separate pack or bottle of anti-freeze to be able to create a solution.

Most of the products listed above are compatible with any kind of anti-freeze. Some products already come in liquid form as a complete solution and are ready to use.

Some products require the car to sit overnight for the radiator stop leak to do its job, while most products require the vehicle to run to be able to do its job.

Again, this entirely depends on the product that you have purchased. You should also consider other factors such as the ones stated earlier to ensure that your vehicle and its components will work well together with the product that you are about to use.

Keep the right amount of fluid, as prescribed in the package of the product purchased, flowing into the system to avoid further damage.

However, if the leaks still persist despite the use of radiator stop leak, it may be high time to replace your radiator to help you save maintenance costs over a radiator that is bound to die anyway.

Keep your tool readily available at all times. The glove compartment may be the best place to store it so in cases when needed, it is easy to find.

Always take it with you, especially when you go on long trips or even short ones so that when unexpected leaks occur, you are equipped and ready.

Final Note

Such products equally function well and fairly have their own benefits, thus making the process of choosing one difficult.

I listed five products above to help you find the best one for your radiator, along with a little overview of what to consider before buying your product and how to use it.

Hope you enjoy our radiator stop leaks review and get some help. Let us know your thoughts via comments.

Morton Turner
 

Morton Turner is the Editor of Toolspost.com. Who is a orbital sander enthusiast and love to share what he know about this field. In personal life he is a father of two cute kids and loving husband of a beautiful wife. He love foods and nothing is more important than reading book in his spare time.

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