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If you use ULTIMATE for a Head Gasket repair and it and it fails to fix the leak get in touch to find out about our money back guarantee. For all our other brands if you have a repair that subsequently fails contact us for a replacement bottle.
Reviews 493
William Bryce
Jun 15,2022My 2018 Ford Escape 2.0 T had the beginning symptoms of head gasket failure (actually it looks like a Ford design defect). Rough idle at cold start and white smoke from consuming radiator coolant. Dealer said 'long block replacement' required, an expensive repair. I used k-seal and the engine now idles properly and no more white smoke at startup. Not sure how long it will last but it is impressive that it worked. I really had nothing to lose trying k-seal since the repair costs are close to $10K CAD.
Lois Cornish
Jun 15,2022I just used K seal in my 2008 Buick because I had a radiator leak and blown head gasket. It worked great but now a month later, it is running hot. Is it possible I need a new thermostat or to have the radiator flushed or both. I hope I get this problem solved as I don't want to trade cars in this market.
Karl
May 28,2022Had a crack in an oil cooler on the turbo, only leaked when engine was cold. Kseal stopped the leak.
John Mentag
May 26,2022Rebuilt a 2019 F150 with 20k miles. After complete, lots of dripping along exhaust pipe led me to believe i had a head gasket leak. The radiator was dry so recovery personnel must have run truck without coolant to overheat the engine. Did my research along with testimonials. Installing K-seal solved all leaks. Cabin heat works normally. Just bought another bottle to fix a 12 jetta. Thoroughly comfortable with product
C Kaps
May 24,2022Ultimate head gasket repair worked 100%. Awful misfire and rattling investigated by garage - camera down showed rusty head gasket due to liquid ingress. Coolant levels down drastically after one drive. I put the k-seal in and followed the instructions and next morning, no misfire, driving fine. That was 3 weeks ago and all is still good!
Sara Grim
May 17,2022After the mechanic failed to fix the leak after a $3000 repair job, we went online and saw the K-Seal review and demonstration on YOUTUBE. We used the product and our car has been running fine ever since! This product worked as claimed for us! Grateful!
Michael Stieb
May 16,2022I had a 2005 Mercedes with a gushing coolant leak, thought a new water pump was needed. Mechanic advised to try KSeal. I didn't have much faith... Bang! 30 minutes, done deal! My 2014 Mercedes sprung a leak last week. Thankfully it did it in town as I had just finished an 1800 mile road trip. I thought, "can it work again?" Poured KSeal in expansion tank, drove 30 minutes. Done Deal Again!
Adilmon
May 12,2022Just a recommendation, K-seal radiator sealant works brilliantly for motorcycles. The result is great. I think it sealed pretty instantly. Of course I ran it until fan came on and off and checked levels repeatedly during about 6 hours of riding. If I go one a long tour, I think a dose of this (1/4 or 1/3 of a bottle) should be packed alongside JB weld for emergencies. Couldn't be happier, especially as replacement is unobtainable and recore is expensive. £12 well spent. (I did actually also by the cheaper Wynns and Holts brand radiator sealant also, but I figured, K-seal only sell one product type, so they live and die buy it working properly) The longer story is I noticed the garage topped up 200ml when she went for a carb tune up. Then when straightening fins I notices a drop of bright green coolant, so I guessed I had a pin hole coolant leak. (maybe 1 drop per 5 minutes) Scoured internet for testimonials, and while none had a glowing review from everyone, K-seal had the best overall ratio of recommendations and lack of complaints. I guessed people are 10 times more likely to complain than sing praise and it was one of the more expensive brands so I gave it a try. K-seal is also one of few that actually mention motorcycles in the instructions and importantly can be poured direct to a cold radiator rather than expansion tank. The particles in the bottle do settle, so shaking and pouring soon after is important. I read a horror story about pouring a radiator sealant undiluted into the core (with fine passages) and it instantly blocking rather than repairing, so I syphoned off some coolant from the rad cap, mixed it well in a jar with the radiator sealant and poured as much back in as possible. Will definitely buy again if needed and will recommend to anyone that'll listen.
David Squillaci
Apr 25,2022Hi , I trusted K-Seal to my 2009 Lexus RX 350. I put the stuff in, but didn't really follow the direction right. But it WORKED. I did buy a new water pump to replace the old leaking one. But K-Seal is holding it together GREAT. It's buying me sometime until I can replace the old pump. Thanxs K-Seal.
chuck
Apr 10,2022Got to admit I never had much faith in stuff like this, figured it was a waste of money, a scam. I got a 2000 Toyota Camry that the head gasket blew or cracked head not sure which but started clearing my personal items out to take it to the junk yard. Buddy of mine come along and suggested K-Seal. I told him I wasn't going to spend $30 bucks for something that's not going to work. I was wrong! This stuff is awesome! I followed the directions and I'm flabbergasted! I been driving it for 2 months now and NO issues. However, I wonder how long it will last? So, the way I see it, if it lasts a few months, I got my $30 worth. Thanks K-Seal!!
Ken Hayes
Mar 21,2022I have a 2010 Ford Ranger pickup, 4.0L V6 with 68,000 miles. Had a recent overheat, poured coolant in, took care of it. Within a couple of days, took it in for an oil change. When I picked the truck up, they told me I was leaking oil and coolant - Blown Head Gasket. In the 10 minutes the truck sat waiting for me to pick it up, two 6 inch puddles of oil and coolant. Being a V6, highly recommended you replace both banks of the V6 even if only one blown. Would have been $3,300. Bought one can of K-Seal Ultimate, ran the engine 30 minutes. Not a Drop! It has been a month, I check under the truck and open the hood every time I take it out, hasn't lost an ounce of fluids! Trucks runs like dream! Amazing product. I bought some time - probably months / year or more - for me to figure out what next, and saved $3,000!
IMPRESSED
Mar 19,2022ASTOUNDINGLY BRILLIANT. Due to a significant coolant leak, at the rear of the engine, I took my car to the local garage. They found the source, searched for a replacement manifold, but found it is a discontinued item, and would have cost in excess of £400.00. I was resigned to scrapping the car, but then I was alerted to K-Seal, which I ordered. I followed the instructions, and the leak was plugged within a couple of minutes. Absolutely amazing just how good it is, what a brilliant solution, I am SO impressed. Should anyone be sceptical, ignore the negative losers and try it. For the money and the guarantee, K-seal is absolutely worth trying before scrapping a vehicle.
Bobski
Mar 17,2022This 73 year old is amazed! Have used every other brand on many different vehicles over the years, any only a very few helped. I truly expected the same with this one especially as it is a water pump leak. Followed your instructions, drove 20 miles or so parked about 30 minutes, checked for leaks and there was NONE. Best leak seal I have ever used…Great product.
Jamey Jame
Mar 03,2022This is an update to another update I wrote in may of 2021, my original post was January 2020. It’s been 26 months since I used kseal to correct a head gasket leak. This stuff is money. I recently had some overheating and coolant loss through the radiator cap and expansion tank and thought F me! It finally went. nope, radiator cap lol. There are many BS products out there that will damage your car, this is not one of them if used CORRECTLY. I’m going to assume that the people that had radiator damage, etc most definitely just poured this right in the radiator. WRONG. I highly suggest that you mix the entire bottle along with at least an equal amount of coolant then add to radiator. once started get the car on an incline if possible and let it run until up to op temperature. Take for a light spin, boom. This will not fix larger leaks fwiw.
Kimberly Jones
Feb 19,2022i used this on a small crack on my radiator that wasnt that bad but was told it needed to be fixed i drove it for 10 mins and looked to see if it worked it did i was so excited i went down the road to store and back home 30 mins tops that i drove it . i poped the hood to check my oil and by the time i checked my oil and shut the hood i have a huge puddle at my feet im radiator is blown . it made my car worse . i do not recommend !!! waste of damn money
Thagodink
Feb 18,2022I woke up one morning and raised my car hood to check battery and noticed my coolant was gone out the expansion tank and I have a Ford Fusion 2014 which is notorious for coolant leaks I’ve been reading and boom it finally happened to me..I was told 8,000 for new engine and of course I didn’t have that to spend at the moment and needed car for work so I researched online and found this product..I was very skeptical but I was desperate nothing to lose at this point. I poured it in my expansion tank and within minutes it worked in disbelief. I topped off my coolant and drove to work 45 miles and rechecked coolant level and was shocked to see that it didn’t budge remained where I left it..I thank this company for making this product so easy to use and affordable they basically saved my life I wish I could repay them..It’s been days now no problem with anything..Thank you k’seal👉🏾😁👈🏾
Pascal Favre
Feb 09,2022Little coolant leak on a Porsche 957 I waited 2 weeks before write this comment & it's working!!! NO MORE LEAK...
James Wales
Feb 01,2022Added ultimate kseal today and it’s foaming all out my exspansion tank overflow pipe ,don’t know if it’s reacted with my coolant at a loss with this one ,followed all instructions so I don’t know if it has worked or not
Mr Alexander Power
Jan 30,2022I have a 2005 Ford Mustang gt only a few weeks ago I was having to top up the Evans coolant every week and the garage found no visible leaks so I added k seal and I have not had to top up the Evans coolant yet hopefully this will be a permanent fix 🙏
Scott Roberson
Jun 18,2022I drive a 2000 Chevy S10 with the 4.3 V6 vortec engine. Noticed a leak and sourced it to the upper bypass hose. Replaced it and noticed water pump weep hole was spraying driver side. Went to Advance Auto and bought the eight fluid ounce k-seal. Let the truck cool in the parking lot for an hour and then added it to the radiator after shaking it for 45 seconds. Added water to my radiator cranked it up and drove it lightly home 4 miles away. Parked it in the shade and let idle for 40 minutes with the defrost on heat full blast setting. Appeared not to have any water flow at this point. Truck was out of gas so drove it up the road and put a few bucks in it, then drove it up the road for a few miles. The temperature stayed at 208°. Drive it a few miles back home and parked it. Turning engine off pop the hood and notice a tiny spray hole coming from the water pump, driver side. At this point I don't know what else to do I tried to call the helpline and it is 11:15 p.m. on Saturday so they are not open. I have to work in the morning and it's a 20 mile drive. Got 2 gallons of water in the back, wish me luck.