1109 PNG

Liquid Copper

What it's for:
  • Block & Head Gasket
  • Cooling System
What it does:
  • Repairs
  • Stops Leaks
  • One Step, No Draining Required
  • Antifreeze Compatible Sodium Silicate Formula
  • Permanent Cooling System Repair
  • Works with All Types of Antifreeze or Water
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It’s part of life: older cars, trucks, vans, SUVs and even RVs can develop larger leaks in their radiators and intake manifolds. If you’ve tried regular stop leak products you know they are not powerful enough to stop these larger leaks. That’s why Bar’s Leaks designed the Liquid Copper Block Seal Intake & Radiator Stop Leak. This one-step sealer was designed to quickly and safely stop these overwhelming leaks.

What’s 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.

Their stop leak products can’t get your show back on the road like Bar’s Leaks — that’s why we’ve been the most trusted stop leak brand since 1947. 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.

Part Number: 1109
Dosage: Use – 1/2 bottle in a small cooling systems, such as 4 cylinders with no A/C. Use 1 bottle for regular size systems, which are most 4, 6, 8 and 10 cylinder engines. For larger systems, use 1 bottle for every 6 gallons of cooling system capacity.
Size: 18 oz. (510 g)

Testimonials & Reviews

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  • “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.”

    Michael M. - Columbus, OH
  • “Thank you, thank you, thank you! I do not have $1500 to repair my 1999 Venture van. Every story I read on the internet about the Chevy Ventures, was that even after having the intake manifold and head gaskets replaced, they still leaked anti-freeze either externally or internally. I just couldn't see spending $1500 on a van that has a book value of only $1200, but still, I needed transportation.

    One day I was in the automotive section of Walmart getting ready to buy another gallon of anti-freeze, when on the shelf right above was numerous kinds of Bar's Leaks products. I purchased the Bar's Liquid Copper Intake and Radiator sealant. At $8 each, I thought what the heck, buy two.

    I have to tell you it's the best $16 I've spent on that 1999 Van, even though I only used one bottle! At $16 for two bottles, it is a good alternative to repair a van, when the cost of repairs is more than the van's worth.

    I have 300 miles on the engine since I poured Bar's Leaks in, and everything is still normal.

    I am so impressed and thankful that I had to write and congratulate you on a great product. I also have to thank you for saving me so much money, and getting me out of a real spot that I could not get out of otherwise.

    Once again, thank you. If it is still running next year, I will write you back and tell you. Thank you.”

    J. P. Costanza - Virginia Beach, VA
  • “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.”

    E. C. - Southern Windows & Doors
  • “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.”

    P. B. - Sunnyvale, CA
  • “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.”

    G. K. - Columbia MO

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