Bar's Leaks Block Seal Liquid Copper Coolant Leak Fix, Antifreeze and Coolants, 18 oz

I've used it in many different vehicles as a stop leak and preventive measure over a 20 year span great product great value highly recommend

Did exactly what it said it would do and it worked. It sealed up a cracked head gasket and it is no longer leaking fluids. Car is no longer getting hot and it runs fine. Definitely worked and it was cheap. Do research before you use this as I've heard it CAN lock up certain engines, but for my Chevy 2002 Malibu it worked fine. Great purchase.

I replaced my water pump, and much to my dismay found another leak somewhere behind and below the pump. I was afraid that the head gasket might be leaking, and used Bar's liquid copper to try and abate the leak. I also removed the thermostat so that this product did not clog it up. This stuff worked great! I have put many miles on the truck without incident....I would recommend using this product should you not want to invest in having head gaskets replaced.

Very good product. Quickly stopped coolant leak, saved $$$’s.

Worked! Coolant leaked stopped 100%

best stuff ever made. It did the trick of plugging intake manifold leaks on two of my trucks!! It was unreal how well it worked. Internal coolant loss is hard to diagnose, but once known where the leak might be, it should be used first and foremost for less than $10. A complete tear down is thousands of dollars!

I purchased this after having a slow coolant leak in my car for a couple of weeks. The instructions were easy to follow and within a couple of hours I could definitely tell that my coolant leak was fixed. It's been a couple of weeks now and my car is still working fine, and no longer leaking coolant and overheating.

It's what I expected and all was good

I put it in my coolant reservoir like stated because my radiator isn't one that has a cap and it didn't go through the system just stayed in my reservoir

My leak may be in a hose or some other component that the leak seal doesn’t work on but after using a full bottle on my 2011 Nissan Juke the issue is not resolved.