Bar's Leaks 1109 Liquid Copper Block Seal, Intake and Radiator Stop Leak, 18 oz. | One Step, Safe for All Cooling Systems

This works great!!! Sealed up a leaking stud within minutes

Daughters old car has had a rough life. Radiator started leaking. She drove low of antifreeze and caused it to overheat but she did not know. She called me saying the car just lost power and would not accelerate. While diagnosing, I found the low antifreeze level. I added just water and quickly found the leak. This daughter has zero cash saved and I've put too much money into her cars because she is not responsibly caring for her cars nor budgeting for car ownership. She has destroyed this beautiful car and it looks awful inside and out. So, I decided to try this product instead of replacing the radiator ($800). The Bar's Leak worked perfectly in just 15 minutes and stopped the radiator leak completely. Great stuff!!!

The stop leak worked great. It arrived just as it was stated it would.

Had radiator leak in bottom of my 2010 Honda Civic with 160,000 miles. Used half a bottle of Bars Copper Stop Leak and carefully followed directions. Leak stopped within a day and heat still works fine. 2 months later and my 2010 Civic is still leak free! Tip for those having issues getting it into system, don’t have radiator full when adding and it helps to use a funnel and reach down and squeeze your radiator hose to help Stop Leak to slide down into system, while adding. Then top off radiator. Ensure you take a decent drive after adding and keep heat blasted to ensure Stop Leak fully circulates through system.

I started noticing drips underneath my rather old car and knew it wasn't worth fixing so i did some research and bought this. I followed the directions carefully: drain some fluid, pour this in, idle for 15 min, and let it cool. After doing so i've noticed no more drips, it's only been about a week so i'll update after a while to let you know if it really lasts but so far it's been great.One note: After running this through the system I did have to clean out the overflow cap which the product had plugged thinking it was a leak. If you notice that when the engine is cool, your radiator hose has collapsed, that indicates negative pressure in the system, in other words it's not drawing fluid from the overflow: clean out the overflow lines and you should be all set.

I decided not to use it after conducting further investigations. Some people said it clogs up their coolant system causing more damage and money down the line. I decided to find the reason for the leak and was glad I did because one of my flanges was made out of plastic and it had a crack so I replaced that with metal.

So far so good,did what it was supposed to

Drain and Flush, put with new coolant and leak product , I follow instructions. Next day pin hole still leaking.