K-Seal Coolant Leak, 236ml | Multi-use Car Radiator & Head Gasket Repair Sealant

Land Rover Discovery Sport 9 years. Leak 1L coolant on the ground every week for a month. After using it for two weeks now, no more leakage! It’s magic!

Great product and fast delivery

There are cheaper (mostly half the price) of many similar ones here in Amazon and elsewhere.Currently topping up my cooler almost every week or two and appears to be small leak as my garage cannot locate it.Last one i used (different brand, such as Holts/Radweld), which lasted approximately 2 months without top-up).Lets see how long this holds up as compared to others as this packaging says 'Permanent'.---- EDIT: UPDATE after 5 months ----Well its not permanent, but long lasting, as after FIRST 3 months needed topup of coolant approximatly 300ml. Then, after another 2 month, same amount, so leak is slowly coming back. I guess i do have a very small leak.But for the price, it is cheaper as I was topping up weekly of similar amount of coolant.

Whilst it might seem a lot of money for what appears to be a child's toy amount (it will fit in your palm) this certainly worked for my engine. Very easy to use, pour it into your expansion tank and run the car as usual. Stopped my leak and saved me from an expensive trip to the garage so this was good value for money. Still performing well after a few months.

Writing from the UK, in December 2022Toyota Auris, 2.0D4D, 2008, 85,000 miles.Had developed a quite significant coolant leak from around the waterpump pulley area - enough to have to top up entire tank weekly. No noise however.With the engine running, I could see droplets of coolant being thrown out from behind the pulley (using a good torch).Tried the K-Seal - according to the instructions - which for me was half this little bottle.After just one drive (30 miles) - the leak had definitely stopped!Now my only concern is - obviously a chemical treatment can't fix a worn bearing (if it is - as opposed to merely a worn seal) - but I'm expecting it to make at least some noise before it's about to do anything catastrophic.A new pump from Toyota was surprisingly cheap (c.£150) - so I will change it out soon.But - where all I have is a worn seal - then this stuff really will buy you thousands of miles, if not tens of.And heck - with it circulating throughout the entire rest of the system - it is also preventive maintenence for any other types of leaks (say heater core).

I purchased a bargain car that I knew would require some work to put it right. When I purchased the car the engine was lacking power and the idle speed was hunting (going up and down). As the engine oil was ok I thought I'd try cleaning out the fuel & exhaust system first using Injector cleaner, turbo cleaner fuel additives and diesel particulate filter cleaner additive to burn off any soot built up in the exhaust. After I'd tried all of those each one on a full tank of fuel I'd probably done 1,500 miles and the car had more power and the idling had improved. I then noticed the car had started to lose approximately a pint of coolant over 10 miles and I think there was a slight whitish haze in the exhaust smoke which shouldn't be there as the car is a diesel. I wondered whether I'd caused the coolant leak by using the fuel additives as they contain detergents. I suspected the coolant may be escaping via the head gasket or maybe via the exhaust gas recirculation cooler into the exhaust so decided to try K-Seal. At first I thought the K-Seal had fixed the leak but after a couple of days the car started smoking again and the coolant loss was about the same as before I had tried the K-Seal. Unfortunately during those couple of days the K-Seal had made a proper mess inside the coolant header tank and as the header tank is made of white plastic lots of copper particles and gunge can now be clearly seen coating the inside of it above the coolant fill level. I have since wondered whether the previous owners may have already used a leak repair to hide a head gasket problem and if so whether it would have impaired the efficiency of this product but have no way to know if that was the case. I decided to try one more cheap fix before considering a garage repair so purchased a competitors product that was cheaper than K-Seal and does not contain all the copper particles. The cheaper product has currently stopped the coolant loss but it would have mixed in with any remaining K-Seal in the engine block so maybe they are complementing each other now. In conclusion, this probably does work in many cases but in my case, it didn't work. I am pretty sure that in many other cases it probably also makes a proper cosmetic copper splattered gunge mess inside the header tank. In hindsight, I think I'd only try the K-Seal again if I could add it directly into one of the cooling pipes so the whole bottle doesn't start off in the header tank or alternatively I'd add it to a warm system so the thermostat would already be open. Also if there is ever a next time on another vehicle personally I'll try the competitor's product first as it was cheaper and didn't make a mess inside the header tank.

Used and results were spot on. Thanks

I had a very slight leak on my '55 Chevy radiator bottom tank. I though this product may have sealed it - not a chance! Made no difference whatsoever. Still had the leak and a cooling system full of useless product. Full cooling system flush, radiator out and solder repaired it successfully. Should have done this in the first place rather than wasting good money on a useless product. Don't bother with this stuff, just do a proper repair.