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

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.

Does what it says on the bottle.

I purchased this product due to a situation where my car was experiencing water leakage from the water pump, leading to overheating. This issue even caused a breakdown on the motorway during a trip from London to Wales. Unfortunately, at the time, most of the local garages were closed for the summer, leaving me with limited options for a quick solution. I had previously used Radwell products, which had worked on two occasions, but this time, it didn't resolve the issue.Regarding the product I'm reviewing, it did eventually arrive, although it took longer than expected. This delayed delivery is the reason I haven't given it a 5-star rating. However, I must emphasize that the product itself performed effectively. Surprisingly, I didn't need to use the entire bottle; half of it was sufficient to address the water leakage issue. I'm currently in the process of purchasing a new car, so my primary goal was to prevent further leaks long enough to visit some dealerships.In summary, if you're facing a situation where your car is leaking, I would recommend trying this product, as it proved to be effective for me.

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).

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!

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.

Had a water leak on my SV650 - wasn't pooling underneath and the exhaust looked a bit white so I think the head gasket was going. I added half the bottle like recommended but that didn't seem to do the trick so I added the rest. It got me through about 10,000 miles until my valve clearances were due and they replaced the head gasket too, so I would say that worked!

Didn't work and had my coolant flushed twice yet it's still full of this stuff.