Best Radiator Stop Leak of 2017 | Buying Guide


Best Radiator Stop Leak

A radiator stop leak is an easy fix for minor radiator leaking and engine overheating problems. Although these are no permanent solution, they at least buy you some time to drive your car to the nearest service center. A radiator stop leak prevents the outflow of the radiator fluid by coating the tiny holes around it. Do remember that even the best radiator stop leak can clog and damage your radiator if you overuse the solution. So, make sure to read the manual to understand how to use radiator stop leak. Here goes our top picks for this category:

Top 5 Best Radiator Stop Leaks

5Dike Temporary Radiator Stop Leaks

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Like most car enthusiasts, I also had a notion that using radiator stop leaks could block the small passages of the engine’s coolant system. Using this product popped the bubble for me. Dike radiator stop leak earned the top spot on my list because of it can be used in simply any appliance housing a coolant system.

Half a bottle of this radiator stop leak will effectively slow down the head gasket seal leak. This will buy you enough time to drive the car for a whole day without having to stop for a mechanic. However, the cornstarch used in the solution may deposit around the overflow tank dip tube, creating a little mess. To sum it up, it is overall a great quick-fix to radiator leakage problems at a decent price.

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4AlumAseal ASBPI12- Radiator Sealer Blister Card

Best Radiator Stop Leak of 2017 | Buying Guide61B78j20oNL

If you’re looking an immediate solution to aluminum radiator overflow problems, AlumAseal could be your best bet. The application is super-easy, and the best part is, it takes only a few seconds to show its effect.  It works equally great with antifreeze systems. Suppose your car’s AC starts to overheat in the middle of a highway.

This aluminum powder will seal the leak, and you’ll be good to go. My friend used it for fixing a small leak in his heater core, and it worked just fine. Do not ever use more than the recommended proportion of the sealant. Doing so will increase your problems instead of solving them. Keeping a can in your car all the time will definitely prove to be a savior in emergency conditions.

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3Bar’s Leaks 1186 Liquid Aluminum Stop Leak

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Bar’s Leaks was the first of its kind to make the use of radiator leaks popular ages ago. The brand has managed to maintain the quality they are known for so many years. The product under scrutiny can repair almost all kinds of minor leakage problems in radiators and cooling systems. You can use for sealing freeze plug leaks, head gasket leaks, small holes in the radiator as well as heater cores.

It is this versatility of application that makes Bar’s Radiator stop leak worth every penny. This particular variation boasts of a formula that works on plastic radiators as well. An immediate fix like this will earn you some time to buy a new radiator or replacement parts for your cooling equipment without any rush. However, the sealant will only be effective for 3 weeks maximum on your radiator so make sure to get a replacement within that period.

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2Genuine GM Fluid Cooling System Seal Tablet

Best Radiator Stop Leak of 2017 | Buying Guide51g0Hco259L

What makes GM fluid cooling system tablets a class of its own is its ability to block leakage as soon as they start. Some of you, I’m sure, have faced instances when you cannot find the source of the leak. Upon filling the reservoir with a pack of these tablets, the leakage problem should be gone immediately.

Not only that, if you’re noticing coolant loss at a crazily high rate, just crush 3-4 tablets into a fine powder, pour it in the radiator and that’s it. Although it doesn’t advertise to be effective on head gasket leakages, I once attempted to repair a very small head gasket leakage. To my surprise, it worked! So, if you weren’t previously sure whether it will work as promised, I’d definitely suggest you to give it a try. It will come handy in situations where many other radiator leaks would fail to perform.

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1K-Seal ST5501 Multipurpose One Step Permanent Coolant Leak Repair

Best Radiator Stop Leak of 2017 | Buying Guide51M52BX9e9L

K-Seal is a multipurpose leakage fix that is specifically designed for heavy-duty engines. It could be a worthy investment for the owners of trucks, tractors or any such vehicle powered by a massive engine. Before getting into further details, let me point it out to you radiator leaks are always a temporary fix and this one is no exception.

It has a wide range of applications viz. head gasket leakage repair, unclogging the engine, fixing cylinder heads, freeze plugs and many more. Some customers I spoke to have also used to seal large leaks in their radiator. According to most of them, two bottles of the formula stopped the flush out of fluids within a month. So, if the problem isn’t too serious, this could be your go-to solution for the time being.

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Effectiveness of a Radiator Stop Leak

It is a big question mark for people out there who ever never used a radiator stop leak before. By now, you already know that these products are only meant for repairing minor leakage issues. And this is not even a permanent solution. Even the best radiator stop leaks would be ineffective after a couple of weeks. Therefore, it is a handy solution for situations when you can’t replace your existing coolant system due to time or money crunch. If used properly, radiator stop leaks can actually do wonders.

What to Look for While Buying a Radiator Stop Leak?

While shopping, you should pay attention to the formula of the stop leak. Not all coolant systems are created equal. The nature of the blowout problem is also variable. Most coolants are either made of plastic or aluminum. Make sure the chemical based solution you’re using is strong enough to seal the leaks without damaging any of the parts of the engine. The easiest way to the right formula is to stick to a top-notch brand.

Due to the same damaging property of these strong chemicals, you should think twice before using a sealant on a brand new car. If the engine or radiator gets clogged due to applying a radiator stop leak, the warranty will be void.


I tried my best to share all my knowledge on this topic with you. When you choose one for yourself, take your time to research a bit more. Also, get it touch with people who have used it to make an informed decision. I hope that helps you buy the best product money can buy. See you then.

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