K-Seal HD Coolant Leak Repair, 472ml | HGV Radiator, Block & Head Gasket Sealant

Amazing! I had quite a substantial waterleak on my free series scans. But after trying this, the leak stopped within about 10 seconds of running the engine. One thousand miles later and still not a drop of coolant leaks out, absolutely amazing stuff.Further to this, the vehicle builds up to the correct temperature and stays there. It no longer overheats, like it did previously with the coolant leaks.If you've got a coolant leak, then this is definitely worth a punt.

Very pleased with the results

Excellent stuff, saved me £1k. Got the car through the MOT & sold. Well worth the money

Sealed up a leak in my cylinder head while I got the money together for a more permanent repair

Head gasket gone on 1.9 diesel, was pressurising the coolant system and overflowing. K seal worked but only when put to the rad pipes, not the header tank.This product caused a block heater matrix though and now it's getting cold I've got no heating

did not stop leak

I was having sudden major loss of coolant, discovered a leaky expansion tank previously and had already replaced tank, but problem then worsened!Couldn't see any obvious leaks from the radiator, and all hoses were sound, unlikely to be the water pump as the problem would have been worse, so likely a gasket or seal somewhere being the cause of the leak.Added 1 container of K-Seal HD, and within an hour or so of the engine getting up to temperature, the leak was fixed with no further loss of coolant. I have put over 3000 miles on the car since adding K-Seal, and no further loss of coolant.Car is Audi A6 Allroad 3.0 V6 Diesel with c.100,000 miles on the clock.Bought another K-Seal to keep in the boot - just in case!

Made no difference