Radiator Stop Leak Concentrate (1196)

Radiator Stop Leak Concentrate


  20 Reviews

Stops and seals antifreeze/coolant leaks. Bar’s Leaks Radiator Stop Leak Concentrate is specially designed to stop minor to moderate cooling system leaks and drips caused by normal cooling system wear and age. It works with ALL types and colors of antifreeze coolant and/or water. Which is one of our commitments to customers: no matter what product you choose, our radiator stop leak or something else entirely, you can also count on effectiveness and ease-of-use.


NOTE: Cooling systems that are dirty or partially clogged should be flushed before usage.

Shake well. Pour Stop Leak into a cool radiator. If direct access to radiator is not available, install in overflow / reservoir tank. One bottle treats 4 gallons. Use 1/2 bottle for four cylinder engines. Fill radiator and overflow tank to proper level and reinstall cap. Drive/idle engine for 15 to 30 minutes. If leak continues, a second application may be required, or mechanical attention is needed. After successful installation, Leave Bar’s Leaks in the cooling system for continued protection.

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At Bar’s Leaks, each of our products is easy to use. There’s no special automotive expertise required. If you can pop the hood on your car, you can use our radiator sealant and other products. Each of our solutions is affordable, costing just a fraction of what you’ll spend working with a mechanic. And each of our products comes with the promise of effectiveness.

Our radiator stop leak concentrate is one of many chemical repair solutions available at Bar’s Leaks. This product is specially designed to stop minor cooling system leaks and drips caused by normal cooling system wear and age. It works with ALL types and colors of antifreeze coolant and/or water.

All you have to do is watch Bobby and Caitlin in our how-to videos and follow our easy installation process. These videos are created to make a simple-to-use product even simpler to understand and apply to your vehicle.


At Bar’s Leaks, our chemical solutions go beyond just radiator leak sealant. We also offer chemical repair solutions for problems related to cooling systems, head gaskets, engine oil, power steering, transmissions and more. As with our radiator sealer, there’s no special automotive expertise required. Each product is affordable and effective, and each works quickly — especially when compared to the cost of visiting a mechanic.

You’ll no doubt find other radiator leak sealant products, but not all of these products work as advertised. In fact, many can actually make your situation worse. At Bar’s Leaks, each of our products is the result of careful research and testing by our top-flight chemical engineers. These professionals are always improving our current products in pursuit of perfection, and they’re also constantly developing new products in response to auto manufacturer innovations and new technologies.

Made in the U.S.A., just an hour outside of Detroit, each Bar’s Leaks product is heir to a legacy nearly 70 years old. We’ve been serving everyday drivers for decades, offering special solutions that are far more convenient and far more affordable than seeking professional help at the repair shop. When you need a radiator leak sealant you can trust, choose Bar’s Leaks.

Get your radiator sealer today.

Customer Reviews

  20 Reviews
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 20 reviews
 by Lamont
Bar's Leaks radiator stop-leak concentrate

I have a 2003 VW Beetle Turbo 'S.' It has a steel coolant pipe which had developed a pinhole leak. It was spurting out so badly, it caused my car to overheat. As a result the car shut down on me. I put an eleven ounce bottle of the 'Stop-Leak' in the expansion tank, after a few minutes of running the car at idle (with the heater cut on full blast), the pinhole completely sealed up and the coolant line stopped leaking. I had been having problems with the plastic expansion tank continually leaking down, but since this 'treatment' the level has held steady. Very happy. It's no telling what this would have cost me for repairs and possibly towing. I am very grateful because my income lately is very limited. Less than $3.50 to make a big hassle go away...an absolute bargain! :-)

 by Bernie L
Heater core leak

Developed a heater core leak in our 1934 Ford Coupe while driving from Canada to the Mississippi Gulf Coast, Crusin The Coast car show. As a service manager for an Ag dealership I tell my customers not to use any additives ever! Going against everything I know I purchased a bottle of Bar's Leak radiator stop leak, added it to the cooling system, ran the engine for about an hour with the heater on high, leak fixed!!! Replaced the heater core when we got back home because I was concerned about what this additive would do to my cooling system and found out that Bar's Leak is an amazing product, virtually no residue of any kind, I could have left the original heater core installed. I also did not need to flush the cooling system. Thank you for a product that works so well.

 by M. K. - Boca Raton, FL

I developed a quart a week coolant leak from my 2000 Mercury Grand Marquis. It was coming from a crack in the small coolant tower integral to the non-metallic intake manifold. These cars were subject to a class action lawsuit against Ford for this problem. I was too late to be covered for this $800 repair so I poured in half of the 10 oz. bottle of the radiator stop leak before a 700 mile trip last week. Leak stopped cold. Thanks, guys.

 by D. C. - Dayton

I heard of your products before, but never had to use it until just a few days ago while I was on the 2010 Hot Rod Power Tour. My 1968 Camaro's radiator started to leak on the tour and I thought I was done and would need to replace the radiator at a cost of around $500 before I could get back home. I purchased a bottle of your Bar's Leak radiator stop leak and almost like magic the two holes in my radiator stopped leaking. I was able to drive the car from southern Illinois to north of Minneapolis without even one drop of coolant being lost. Thanks for a wonderful product and I would suggest to anyone that is going on a trip to have a bottle of this product in their trunk for an emergency. Even if you don't use it, there maybe someone out there that just might.

 by C. W. - Tacoma

Hi, well here it goes, I drive a car that has a lot of miles, over 200 thousand on it. Well I had a leak that wasn’t huge just really bad. Well I’m not going lie about it I did use other things from homemade things to over the shelf products with good things talk about. Then I went to my local auto parts AUTO ZONE and told the clerk my problem and the clerk took me to your product. I had a lot of questions but I was told by the clerk it was the best there was for what was wrong with my car. I used it like the directions said, you can say I haven’t been happier with a product, it really did what it said WOW really WOW. My car doesn’t over heat, and it doesn’t leak! I have my car back, before I found your product, it was 3 gallons of anti freeze a month. Well in the end of things you have a great product here, this is the first time I’ve ever did a testimonial for anything. Thanks!

 by F. S. - Bardstown

After roughly 270,000 miles, my 1993 Crown Vic developed a small radiator leak. Poured in a bottle of your radiator leak stop, drove for a couple of days and coolant level has remained constant ever since. Great product, works as claimed, which is rare in today's market place.

 by B. L. - Loudon

For your product I thank you very much. Me and my girlfriend went out on Valentine’'s Day and we were stuck in traffic and the car started smoking. We pulled off and got the car stopped for a while and went to the nearest station and saw that the radiator was cracked, I went in the store and they had 2 bottles of radiator stop leak left. I purchased both of them (because I have a V-8) and poured both of them in and took off. We drove for 70 miles to the house and it still works great!!! Thanks Bar's Leaks!

 by S. A. - McKinney

I just wanted to tell you a testimony on your product. I poured in the bottle last night, and drove for about 30 minutes as the direction suggested, and voila, my radiator was full of water this morning. I was amazed, because I was pouring two gallons of water in the radiator every day, because people had said that these products clog the heater core.; But, when I searched your site and read FAQ, I was assured your product will pass through the number 24 screen which big three cars have, so I decided to try, and I am very pleased; I bought another bottle just in case I need to add more, but I didn't need to. I will probably use it next year again as you suggested for maintenance.

 by W.W. - Fayetteville

I want to comment on your Bar's Leaks Radiator Leak sealant. I had a very small leak on my '02 Silverado, and was adding coolant every week. I was afraid I was going to have to pay a mechanic hundreds of dollars to tear my engine apart in order to find the leak. I read about your product on another web site, so I thought I'd give it a try. So, I topped off my coolant and added your product. One week later, my coolant level is exactly where I topped it off at. Thanks for making a great product, and saving me lots of money.

 by Miguel - San Diego, CA

This product really helped me out, I had a cracked cylinder head and for a second I thought it wasn't gonna work but just had to pay really close attention to the directions, my last step was putting more antifreeze in the radiator and ever since it has stopped leaking, in at 186,000 miles with a 01 grand Cherokee Laredo, will update any changes in the future. Thanks for the help amigos! Saved approximately 1000$-1500 on parts and labor.

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