Liqui MolyRadiator Stop Leak | 250 ml | Cooler additive | SKU: 20132

I like to always keep a can of this in the garage just in case. It always seals without clogging anything, as it remains liquid except for the amount it takes to seal the leak. My last repair was pretty mundane, but before that I used Liqui Moly to repair a plastic radiator that had a hairline crack on one of the end tanks. Not only did it seal the crack, it lasted two years before a different crack developed. I decided to use another bottle of Liqui Moly (I had replaced the coolant some time in between, so there was no longer any product in the system), and it worked just as before. A few months later, I was driving home when I saw steam rising and my temperature gauge steadily rising, so I pulled over. I figured that the Liqui Moly had failed at some point, but upon inspecting the radiator I found that the hose mount and most of the end tank had broken off, causing a major loss of coolant. Once the car was back home (thanks, AAA!), I further inspected the broken piece and discovered that I could see the previous cracks that the Liqui Moly had sealed within the larger broken piece - Liqui Moly was still doing its job, even though it didn't stop the giant crack from happening. And yes, I replaced the radiator at that point, along with all of the hoses and the water pump. The old pump still looked like it was in great shape and showed no sign of clogging or sealant residue, which boosted my confidence in the product. I still have that car and it still runs great, by the way. I also just recently had the timing chains done on another car, and it seems the mechanic left one of the radiator hoses loose. I tightened the clamp, which fixed the issue, but it reminded me to order another bottle of Liqui Moly to keep on hand. I know that if I ever need to use it again, it won't mess up my cooling system.

Very helpful, stopped my coolant leak. Just poured it into the plastic reservoir and drove for 25 minutes. Next day checked, no leak! Great product!!

My radiator have a hairline crack and coolant is slowly leaking. It was winter time so there is more pressure on my lines because I have to use my heater. This sealed the leak and I am not losing coolant anymore. This looks like it will hold for long until the weather is warm enough for me to replace my radiator, or when it start leaking again.

Used on a BMW 2011 E90 SULEV radiator. it had a very small leak and paying 600 for a radiator was not on my books. I normally never use additives for my car. ive had this car from new and its got over 200K miles by using good parts. i was very hesitant to use any products for this. however, liquid moly has always proven be a great reliable source for my car. i use it for my oil and such. so i have real faith this will hold and not screw up my bmw. so far the leak has ceased and the car has been running top notch.

My porsche cayenne s had a bit of a coolant leak coming from the thermostat housing, i would have a small puddle every morning, i thought i would try this radiator leak by liquimolly, i followed instructions to the T and within 5 hours no leak and its now been a month and no leaks and engine temp has been stable and havent had to top off coolant ever since. If this can hold for at least a few months until i decide to permanently fix the leak i will say it is more than worth it.

Used on 2014 F150 with 150K miles

It works perfectly to cover the very small hole

Didn't work for me 2006 honda civic 1.7L