Liquid Copper (1109)

Liquid Copper


  38 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

  38 Reviews
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 38 reviews
 by Dan L.
Worked like it claimed it would

Bar’s Leaks helped with a problem I expected to have to pull the engine to repair. I had a freeze plug that did not seal correctly on a fresh rebuild on the back of the engine where the trans bolts up. It was weeping, not really leaking. Constant coolant smell when hot. I tried Bar's Leak's Liquid Copper Block Seal but really didn't expect much. I was amazed that it took care of the problem without any drama. Worked like it claimed it would. It hasn't leaked a drop in a few years now. I am usually very skeptical but based on this product's experience I would definitely try another Bar's Leaks product if needed.

 by Randy R.
Fixed friend's Impala

Hello, I used the Block Seal product. It was on a friend's Impala that had a leak that was annoying him. I suggested your product that I have used in the past. Poured it in and he hasn't had an issue since. Great products!

 by Jose
Car repair

I've used this on emergencies while driving work in the oilfield. Saves me money and time before costly repairs when a mechanic shop is nowhere near.

 by JP
Best stop leak I've used and you will ever find

Without a doubt this is the best I have ever used. In various vehicles I have tried my variety of stop leaks and decided to try this product from Bar's Leaks long ago. So far it has permanently solved leaks in several heater cores (ours as well as friends I have referred) also 1 radiator and 2 intake gaskets on a GM engine which always leak.

Unless you have a gaping crack in a head because you already overheated your car, or you have a crack in the plastic ends of your radiator, this stuff will save you. Obviously it will also NOT fix a leaking hose.

Also, if you have already put 1 container in your car and still have a leak, you already have bigger problems than this can solve. Adding another bottle will only make matters worse.

 by DeathRoe
Liquid Copper

Works exactly as advertised! Im blown away by the almost instant fix this product worked on my severely cracked radiator. My front end was damaged by another motorist in a collision, I was filling the radiator every 5 miles! I just hoped this product could buy me some time 'til payday, but since using Bar's Leaks I haven't had any more problems!

 by Paul Taylor
Block Seal, It's a miracle

My 2000 Ford Ranger had a bad head gasket to water jacket to oil channel and compression leak as well a a perforated radiator, figured "what the hell, I'll give it a shot before I tow this rust bucket to the junk yard". I picked this product up at Oh Oh Oh O'Reilly's and just in case stopped by Saint Alfonzo's and got Father O'Callahan, funny name for a Nigerian priest, to bless the bottle and sprinkle a little holy water in it, hedging my bets I lit some incense at the Buddhist Temple on the way home. Following the directions I let the engine cool completely down, popped the radiator cap and poured in the whole bottle of Bar's Stop Leak Block Seal Copper then topped off the radiator, which wasn't easy 'cause the water was running out of the holes in the radiator pretty fast. Started the engine and within a couple of minutes the radiator stopped leaking and within ten minutes the formally rough running engine was purring like a kitten. Let it go for the full 15 minute warm up recommended on the bottle then took the old gal over to the Dyno', I had picked up and extra 24-1/2 HP and the MPG was up a good 30%! Either this product is a MIRACLE or it is just my lucky day! Woo-hoo, I'm off to buy a lottery ticket and some Viagra and heading downtown!

 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.

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