K-Seal ST5516 Heavy Duty 16oz Multi-Purpose Formula - Ideal for Truck & Tractor Radiator Coolant Leak Repairs

Raetz FamilyRaetz Family: Had a leak on our tractor at work unfortunately it was pushing the weekend and shops were closed had to come up with a quick fix and this works great! Sealed up the leak until we could get it serviced and allowed us to finish up the job we started. Thank you I definitely would recommend it to anyone

United States on Nov 10, 2023

Peter: Poured K-Seal in an old John Deer with head-gasket leak. Worked first time, no more leaking into the engine oil of coolant.

Now after 2 months leak still gone... Amazing

United States on Nov 04, 2023

Amazon CustomerAmazon Customer: Blown head gasket on my backhoe...antifreeze mixing with oil bad!! I really had my doubts that this would fix the problem. I mixed it in a jug of antifreeze and poured it directly into the rad...fired her up and let her run 40 mins. It normally over heated on 5 mins with leak but 40 minutes latter gauge on the green. Next morning I fired her up and filled up rad and holly crap it held!! I checked everyday for 5 days in a row and never dropped. Just amazing stuff!! It did not effect my heat in tractor at all everything works as it should!! This stuff does what it says it does!!!

Canada on Sep 03, 2023

Neel: My neighbour swears by it. Says it fixed the leak on his truck perfectly and that was a year ago and the fix is still holding up! He only used half the bottle too so he still has the other half left.

We however did not have as much luck but that was our own fault! We had a small leak at first, if we had known about this product and used it then, I feel like it would have definingly solved our problem! But we unfortunately ran the truck to the point where all the anti-freeze leaked out because we had bad head gaskets and it over-heated the engine and then unfortunately this couldn't fix the major problem we created.

I would definitely recommend this if you have a coolant leak, use it early it will definitely help!

Canada on Jul 15, 2023

George Richardson: Didn’t work as a ounce

United States on May 31, 2023

Kamkangaroo: Did not work

Canada on Mar 05, 2023

Hyder Ali: It fixed the problem only for 2 months or 1000kms on drive,i use s300 2004 model

India on Jul 17, 2022

Hugh G. Rection: I went into this thinking it wouldn't work at all and possibly cause other problems. Minor head gasket leak that was getting into the combustion chamber and blowing out the exhaust, but not getting into the oil. I would watch a small bubble rise into the overflow tank once every couple seconds, and over the course of 100 miles or so would be putting in a half gallon of coolant. Since it was fighting against the compression I doubted it would be able to work its way into the hole and plug it up.
I followed the "less is more" method that others on here had good results with. I drove the car to work to get the coolant up to temperature so the thermostat would be open and ready to cycle coolant. Got to work early and poured roughly 4 or 5 ounces of what looks like robot vomit into the overflow tank, turned the heater on full blast, and let it idle for about 30 minutes with the cap off the overflow tank. I watched the typical bubbles come up into the tank every time the cooling fan would kick on, but noticed they stopped appearing on the last couple cycles. 9 hours later drove the car home as usual and checked again when I got home, no bubbles and coolant had remained at the level I...

United States on May 17, 2021

Ravi: i poured 200 ml for my 7.2 l coolant capacity radiator. then ran idle engine for 30 min. It sealed whatever head gasket leakage was present. The service station asked 15,000 to replace head gasket. This cost much less - 4400. Excellent product.

India on Apr 24, 2021

Daniel B. Peeks: I took my 2010 Land Rover to a mechanic because it was leaking coolant. The exhaust was sweet-smelling and there was no coolant dripping from anywhere in the engine bay. I suspected a leaky or blown head gasket. I let the car sit for 3 or 4 days and upon start up there was a big puff of white smoke and I got the check engine light. Cylinders 4 and 6 had misfired upon start up. I took it to a mechanic to get it checked out and he confirmed a head gasket leak with an estimated cost of repair approaching $10k. I decided to look for a cheaper alternative to at least postpone having to spend so much money on a repair on a car I had just purchased (used with 110,000 miles) and I found K-Seal. I read another reviewer who suggested not putting in the recommended amount, but just a few ounces, which is what I did. I put in between 2 and 3 ounces into the coolant reservoir and followed the instructions. The car has a 5 liter V8, which is small compared to the engines K-Seal is designed for, so that made sense to me.

I took the car to another mechanic to get a second opinion about the head gasket after putting in K-Seal. I told him I had put a gasket sealer into the car and he poked...

United States on Mar 30, 2020