Liquid Copper (1109)

Liquid Copper


  32 Reviews

What does it do? Our formula permanently repairs larger leaks in radiators, intake manifolds and gaskets, heater cores, blocks, heads and freeze plugs. It contains an antifreeze-compatible sodium silicate liquid glass formula, so no draining of the cooling system is required. Not to mention, it will not harm the cooling system when used properly. The intake gasket seal you’ve been looking for is far more effective, easy to use, and less expensive than you’ve ever imagined. This is why Bar’s Leaks exists: to offer usable, low-cost intake gasket seal and other products to auto owners who have no special experience or expertise. We’ve been doing this for over 70 years, so we know a thing or two about chemical repairs.


  1. Allow engine to cool. Make sure engine is cool enough so radiator cap can be safely removed.
  2. Shake well. Pour Bar’s Leaks Liquid Copper directly into radiator. If using in a small cooling system including all 3 and 4 cylinder engines, use 1/2 bottle. TIP: If direct access to radiator is not available and if overflow tank is pressurized, you can install in tank.
  3. Fill radiator and overflow tank to proper level and reinstall radiator cap. Start engine.
  4. Turn heater on hot and fan on high.
  5. Idle engine for 15 minutes.
  6. Turn vehicle off and allow engine to cool.
  7. Top off (fill up) radiator and leave Bar’s Leaks Liquid Copper in cooling system for continued protection. Drive vehicle as normal. For severe leaks, like a blown head gasket, it is recommended to use Bar’s Leaks Head Gasket Fix or professional-grade HEAD SEAL™ Blown Head Gasket Repair.

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You’ll find plenty of options when searching for products to fix an intake gasket leak. While our competition may claim to stop the leak quickly, their products don’t always perform as advertised and they sometimes make things worse. Their stop leak products can’t get your car back on the road like Bar’s Leaks — that’s why we’ve been the most trusted stop leak brand since 1947. Throughout our long history of serving car owners like you, we’ve used a team of dedicated chemical engineers to constantly develop and refine products that are safe, fast and effective in stopping intake gasket leaks and other automotive problems — including liquid copper and much more. Make sure to watch Bobby and Caitlin in our handy how-to video so you can become a “three-minute mechanic” and finally take control of that leak.


When you’re experiencing mild to moderate leaks, including intake gasket leaks and leaks related to power steering, engine oil, cooling systems, transmission and other key systems, in your car’s operation, Bar’s Leaks has the power to stop those leaks quickly, effectively and affordably. As the best-known stop leak brand in America, we have a long history of creating products that even the novice auto owners can use to extend the lifespans of their vehicles and, best of all, save money by avoiding costly repairs. Our products are made in America, just an hour outside of Detroit. And we can look back at nearly 70 years of service and point to millions of customers who have used our products to their satisfaction. At Bar’s Leaks, you’ll find intake gasket seal in the form of liquid copper, plus other effective products, that fit perfectly into your lifestyle and budget.

Find where to get your Liquid Copper today.

Customer Reviews

  32 Reviews
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 32 reviews
 by Roli toquero
1109 product

I just bought Bar's Leaks 1109 radiator repair for gaskets and sealer. I poured 1 bottle on a v6 engine Nissan Frontier the problem is losing a lot of coolant and going to tailpipe. I’d run the engine idle for 15 min as instructed in the bottle , after that let cool down and add anti freeze and drove for 20 miles. The steam coming out of the tailpipe is gone. Now I need to drain the oil due to moisture. My engine runs smooth now just like new tune up. Will recommend this product.

 by Duane L.
Intake Manifold Leak- Liquid Copper

"Thank You" for making an awesome and effective product!

Recently, my 1997 Ford Aerostar van with the problematic 4.0 liter engine began moderately leaking antifreeze from the intake manifold. After coming to the conclusion that a repair would cost more than the value of the van, I decided to try the Bar's Leaks Liquid Copper. I called you guys and your representative informed me that Liquid Copper was one of your best products so I decided to give it a shot. I flushed out my radiator and refilled with fresh antifreeze and a bottle of Bar's Leaks Liquid Copper. The leak was initially active when I started the vehicle but it sealed a few minutes later as soon as the thermostat opened and the engine approached operating temperature. I then drove the vehicle on a 3 hour road trip and successfully made it to my destination and back home again with no issues. I use this vehicle for a traveling Top 40 Variety band which means we are always on the road traveling in the late hours of the night into early morning. Many miles have passed since adding your product and my 1997 Aerostar is still going strong and has not leaked a drop of antifreeze since adding Liquid Copper into my radiator.

Thank you again for making a reliable and affordable product. I can now say from experience, your products do work as advertised and there is a reason the Bar's Leaks company is still in business and prospering after all these years.

Keep up the great work !

 by Cody C. - El Reno, OK
Love your product

I have been using your product for years and last night my truck lost all it's coolant. I told my friend to bring me some water and a can of Bar's Leaks and once again your product worked and I was able to drive the 342 miles to my house and still drive it. Love your product. THANKS BAR'S LEAKS.

 by Michael M. - Columbus, OH

I want to leave feedback... I used the Bar’s Leaks Copper Block Seal on my 2000 Caddy STS. Before I used this stuff my car could only run for about a mile before it started to overheat. I tried a couple of other fixes, the ceramic, the fiber which both made you flush your cooling system before you even added the crap. Then I used your Copper Block Seal and it worked. I paid over $150 for a treatment of the ceramic stuff and it didn't do anything, the fiber ceramic didn't do anything either. They were both a waste of money. Your Bar’s Leaks Liquid Copper Block Seal is the best s**t I have EVER used.

 by E. C. - Southern Windows & Doors

I've used Bar's Leak several times over the years, but you have so many products available now that I really didn't know what to use. Thank you for recommending Liquid Copper Block Seal for the intake manifold leak on our 1999 GMC. It seemed to work immediately and hasn't leaked a drop. Good products, good website and great advice. Thanks again for your help.

 by P. B. - Sunnyvale, CA

I had a head gasket leak that was requiring me to replace about a gallon of coolant every 2 days. After using only 1/2 of a container of your Liquid Copper Block Seal [because disconnecting the return line to the radiator, I could only pour in that amount], the problem vanished. At some point I do need to repair the head gasket, but your product has bought me some valuable time.

 by G. K. - Columbia MO

Hello, I used your product with great success the last nine months. After a blown head gasket, I applied your product and it immediately sealed the leaks. Just today after checking my radiator reservoir, I noticed some very small copper-looking particles floating on top. There seems to be no water in the oil and no white smoke form the tail pipe. The car is running good and not overheating.

 by J. L. - Bolingbrook, IN

I had a significant cooling system leak from the radiator on a 2001 Cherokee. I put in the Liquid Copper Block Seal Stop Leak, followed directions on the bottle, and.... NO LEAKS! I can't say enough about a product that delivers as stated. A plus is it’s made in the USA. I'm a customer for life.

 by L. M. - Fairfield, WI

I was working on a friend’s car as a favor. After a full tune-up, the car still had a rough idle. I decided to take the car home where I could spend more time on it, I didn't get too far before the car overheated leaving me stranded on a bridge of a major highway. The car had a blown head gasket and would blow the coolant out faster than I could add it. There was no way I could use any of the other sealants that require flushing, adding the sealant, then flushing again. I bought one bottle of Bar’s Liquid Copper Block Seal Intake & Radiator Stop Leak. I didn't expect it to work at all, but it was the only thing that I could think of without having to fork out $150 to have it towed. I poured one bottle into the radiator, added some coolant and by the time I drove it back to my friend's house, it was running great. I couldn't believe it. The car is still running great. I can't even tell you how much trouble, time, money, and stress your product saved me. Thanks!

 by C. D. Skandia - Grand Haven, MI

Bar's Leaks, I've got to tell you that your Bar’'s Leaks Liquid Copper Block Seal must be some kind of miracle in a can. Instead of the $800 bill the mechanic said it would cost me just to find out why engine coolant was getting into the engine oil, not counting the parts yet, I spent $10 on your product. It immediately fixed the coolant leak, which was bad. Then I get a $5.00 rebate on top of that, which I felt guilty about even taking. I never had any faith in quick fix cures for machinery, but I do now in your product. Thanks so much!

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