Radiator Repair Stop Leak


2015-02-15 15.38.24What is Radiator Stop Leak?

Radiator stop leak is a powder or liquid solution that is added to your cooling system to help stop and prevent leaks. Cooling system stop leak works best on small pinhole or seeping leaks.  In most cases, it can be easily added to your coolant offering you a fast and simple radiator repair. The true value of radiator stop leak is the time it gives you to get into a repair shop.

How Does Radiator Stop Leak Work?

When stop leak is added to a cooling system, it forms a coating over small leaks and helps slow down or stop the leak. Some stop leak acts like a plug and just kind of blocks up the hole from the inside. As you will see from the list below, many stop leak additives, are no more than blocking and plugging material. Radiator sealant should be considered a temporary fix that could eventually fail and allow a leak to return. In an emergency situation, stranded on the road, radiator stop leak can buy you the time you need to get to a radiator repair shop. In certain situations, radiator coolant stop leak is the best way to slow down or stop a leak.  A water pump gasket leak on the road may be impossible to slow or stop using anything but radiator stop leak. In the event of a cooling system gasket leak, stop leak may be your only choice. If your vehicle breaks down along the side of the road, a radiator leak repair kit, kept in your vehicle, that includes coolant stop leak is a smart idea and a great way to get you moving again.

Should you use radiator stop leak?

If you ask ten people if you should use cooling system stop leak in your vehicle you will get five against it and five for it. The correct answer is that it depends on your situation. There is no simple right or wrong answer to using radiator stop leak. In all my years of working in a radiator repair shop, the basic stop leak review always comes back as, you use stop leak when you need to use stop leak.

If you’re driving a $75,000 vehicle and you get an antifreeze leak smell and find that the radiator is leaking, take it into a radiator repair shop and have it fixed properly. If you are losing fluid quickly, then you should call a tow truck. Never drive your vehicle when overheating or if your engine temperature light is on. If you have a $75,000 vehicle and you are on the road in the middle of nowhere and a small leak starts shooting fluid out of a water pump gasket, put a little stop leak in and get to a shop. If you have a $1,500 old pickup truck that they want $450 for a replacement radiator plus labor, and you don’t have that kind of money, use some coolant stop leak and keep a close eye on the cooling system and see if that works. The key here is to watch the temperature and coolant level. If you will void your warranty by using stop leak to repair your radiator, just don’t use it. Call a tow truck and get to a repair shop.

What is the best coolant stop leak?

Depending upon what part of the country you are in, you will get a wide range of strange answers to this question. So, what does the radiator stop leak reviews say is the best stop leak? Your choices are: an egg, a liquid called spot weld, sodium silicate or water glass, chewing gum, bars stop leak, Peanut shells, K-Seal, bread, Alumaseal, mustard, Dike temporary radiator stop leak, CRC Heavy Duty radiator stop leak, silicone seal, Marine Tex, pecan shells, golden eagle, walnuts, ITW Global, almonds, ginger, Prestone radiator stop leak, Pepper and coffee grounds. Please note that this is a partial list. The best stop leak additive is anyone’s guess, and you should make sure you follow the directions on the package. Bar’s leak is probably in every part store out there so that may be a good choice for you.

Stop leak concerns

Using radiator stop leak can cause clogging of the cooling system. Depending on what type of stop leak you use and how much you use you could plug up your radiator, heater, and engine. Clogging can occur, and the key here is making sure you change your antifreeze and flush your cooling system according to manufactures recommendations. If you use stop leak and then get your cooling system repaired properly, it would be recommended to power flush the whole cooling system. Don’t just drain the fluid, get a power flush. Flushing the system and changing antifreeze when called for will help keep your cooling system running properly and help remove excess stop leak from your system.

Does stop leak work?

Radiator stop leak works if used correctly and in the right situation. Coolant stop leak has been used in new vehicles for years, and rumor has it that it is still used in brand new vehicles. GM used Delco Coolant pellets with the Northstar engine. The sealant tabs were intended for nuisance leaks. Anytime we did a flush on a Northstar engine we had to add the Delco pellets.

Block Seal and Gasket Fix

Block Seal and Gasket Fix

There is stop leak for head gaskets, oil stop leak, transmission stop leak, engine stop leak, tire stop leak, and stop leak is added to vehicles all the time for various leak situations. It just provides extra protection against leakage. While many will say, stop leak is bad, there are millions of vehicles on the road today that have stop leak in them. You need to think of stop leak like a tonic. The key to using stop leak is the right amount is enough and just don’t keep pouring this stuff into your cooling system. Preston and other antifreeze suppliers even have stop leak antifreeze that helps keep the cooling system free from leaks.

In our radiator repair shop, we would use stop leak if the situation required it. If we had a radiator that was not repairable and putting heat to it would just have it fall apart, we would offer the customer a patch. If a vehicle was not worth spending money on and the customer just wanted a temporary fix, we would solder the large leaks and use a product called SpotWeld by the Barbee company. SpotWeld is a liquid solution that would stop all kinds of small radiator leaks. We called this stuff Radiator Man In a Can and it worked great. We would even use it to stop slight head gasket leaks. We sold a 5 gallon can of SpotWeld to a train maintenance yard, and they put it into a locomotive engine. SpotWeld sealed the head gasket leak on the train!

In an emergency situation, radiator sealant is a good option to help with a radiator repair, a leaking gasket or a leaky radiator hose. Stop leak does exactly what it is supposed to do. Stop leak helps seal and prevent leaks in your cooling system. It is not permanent and will have to be checked as soon as possible. If you are stranded with a cooling system leak and have radiator sealant, I would use it. The choice is yours, stop leak does not work all the time but it is a great way to get you going again in many situations.


Bar’s Leak

Spot weld stop leak

Barbee Company




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