20 Best Heater Core Stop Leak (2023 Updated)

I couldn’t find where i was loosing antifreeze. No drip or spots under my truck. Must be internal. I bought the bars leak l have used before and it worked. I just had the thermostat and the housing changed a few months beforehand.

Now its working great.

It stops the leak, but it also clogs the overflow hole and hose at the cap. I noticed the upper radiator hose was collapsed after driving and letting it cool a bit. Upon removing the cap, air went back in the system and upper hose expanded to normal – which is when I noticed the material from the product clogging the overflow hole and tip of the overflow hose.

I removed the clog once, but after driving just 2-3 miles, it clogged the overflow hole again. Ended up ordering a new radiator, since this is a temporary fix anyway. Just be aware that this might happen and overheat the engine, especially if you have too much fluid or it’s overflowing at all.

FYI, my fluid is at the max line and this is a Chrysler under 10 years old, and the overflow hole is about a quarter inch in diameter.

I have a coolant leak in my 2002 VW New Beetle. I know it needs to go to the shop, but I was 120 miles away from home when the problem developed. In what I considered to be an emergency situation, I added half a bottle, as per the instructions.

In fact, I would say that the coolant leak decreased by 80% or more! Got me in, and was considerably less that the cost of a tow. Going to the shop for sure, ASAP.

Awesome product. My TJ Jeep Wrangler started leaking it’s anti-freeze and couldn’t find the leak. To ease my mind while driving and avoid getting stuck out on a road with a “steaming” radiator, I poured Bar’s Leaks Liquid Aluminum Radiator and Heater Core Stop Leak.

The product started right away and I could see that no leaks after driving around with the solution inside my radiator. There was a “funky” smell for a couple of minutes but I am guessing its either the surrounding area (have my windows open) or from the product.

Either way, the smell dissipated after a few minutes. Jeep’s running well and smoothly again. I might replaced the radiator and replace the hoses too, Meanwhile, the Bar’s Leaks Liquid Aluminum Radiator and Heater Core Stop Leak, is still providing solid performance on a very hard working Jeep engine.

I tried this plus Jb weld radiator repair kit. My oem honda radiator lasted 300k. After spending lots of money recently on needed repairs. When the radiator gave out with a slow leak. I tried putting this stuff in plus Jb weld on the crack.

Worked for a week or so then starting leaking again. Ended up getting new radiator, hoses and thermostat. When draining the stuff is little metal flakes probably all over the engine and water pump ect.

Not good will need to flush out again. Bar makes great products. But this does not work for every car.

Have a 2004 Kia Rio I’ve been doing a lot of work on. Just when I think I’m done, something else pops up. (I’m sure you know the feeling. ) Radiator started leaking. Before I freaked out and bought a new one, I did my research and discovered this.

Over the last 2 years I’ve added about a bottle-and-a-half. I get a small leak, pour in what I can till radiator’s topped off and that’s it. Six months later another small leak. Lather, rinse, repeat – lol.

Imagine if I waited a bit or drained enough out to add a full bottle, might really seal it up but this way seems to do fine. All I know is I haven’t had to replace my radiator yet! Yay! :D.

My review is not incentivized. This stuff really works. My cobalt was leaking antifreeze so bad to where my coolant would be completely empty after filling it completely full within 2-4 days depending on how much I was driving and would still leak even if it was just parked.

I have tried other liquid type stop leaks on other vehicles in the past with no luck so after finding this pellet type I figured I’d give it a try before I took it into the shop. I only used half the bottle as directed and then immediately took my car on a about a 30 min drive around town to let the pellets have time to melt and seal holes.

Over a month later now I still haven’t had any leaking issues since. I will definitely recommend this product to everyone I know. You can’t beat the price for it either.

I replaced an old Radiator and it started leaking fluid from my water pump seal. On referral from my brother who’s worked on cars 40 years said give this a try first. Well, it worked! Didn’t have to replace the gasket.

Well then it went to next weakest point. Hose connection started leaking so, replaced old pinch pressure clamp with a new hose screw on clamp. That worked and well now my AC unit has a small leak in one of its hoses that has a crimped collar to a metal connector.

So, I’m living with that till I get to my nephew who does AC work. So, I’ll say it works on leaky seals! Also, Thanks to another review who said you have to split the amount of liquid and pellets depending on your radiator size.

Have two plastic cups handy you can see through and a funnel.

My radiator developed a large leak, a new radiator is about $200. 00. I have tried stuff like this in the past and they are usually temporary fixes. My Ford Taurus doesn’t allow direct access to the radiator it has a large plastic reservoir.

I called Bar’s Leak advice line and they recommended PLT11. They said to mix the can of stop leak in a container with hot water first to dissolve the pellets and remove the top radiator hose and pour it in there.

It stopped the leak immediately. So far so good, only time will tell.

Without a doubt this is the best stop leak I’ve ever used. I have tried plenty on various cars and came upon this one years ago. So far I have used it to permanently repair several heater cores on our own as well as several friends and family member over the years.

Also have fixed 1 radiator and 2 gm intake manifold leaks (very common). A couple years later and still going strong. Just some things to know. This stuff performs miracles but it can only do so much.

If you have put in 1 bottle of this stuff and it did not solve your problem then you probably already over heated your engine and caused a crack in the head too big for any sealant to fix. Also it can’t fix plastic radiator end cap leaks or hose leaks.

Yep, there are people I’ve known dumb enough to think it can. And don’t put in more than 1 bottle or you will make problems worse by sealing up every water passage in your car. More is not better here.

My van was not overheating, just leaking so I used this in my coolant system when I could not find where the leak was coming from. On the bottle it says you do not need to drain the coolant, but it did not specify that you need to have fresh coolant.

After using this product my car overheated in less than 15 minutes. When cool I checked the levels in the radiator and found that there were fiber-looking clumps all throughout. After checking the website “You must apply our stop leak products to a clean fluid system.

” My radiator was rusty and had calcium deposits before using this, but if the bottle had indicated this disclaimer I would have done a formal flush before using it. I then proceeded to use various radiator cleaners to try to get the fiber clumps out to hopefully get the overheating to stop.

The glitter is still there and holding strong after 5 flushes with no indication of stopping. I think this product would have been great if it hadn’t bonded with the rust in my radiator, but I had to replace it because it sealed up the fins.

Rating it low because the directions on the bottle are incomplete.

This product will stop your leak. It’ll also stop coolant from flowing, thus stopping the leak. My 98 Expedition had a small intake manifold gasket leak. Added this per the instructions. Seemed to work for about 6 weeks, then I noticed the heat wasn’t working well.

Eventually started blowing cold air. It clogged up BOTH heater cores in the car. I always said that a mechanic in a bottle never works, yet every 5-10 years I give them a shot. and ALWAYS regret it. Do not use this stuff unless you’re just trying to get a few extra months out of a failing vehicle.

That is all it’s good for.

This stuff works as well as it needs to. I was able to see this work in real time. My plastic radiator drain plug broke off when trying to perform a coolant flush. I had to drill a hole in the plug before using an extraction tool to remove it.

A stream shortly turned into drops. I had to redrill the hole several times because this stuff clogged the hole so well.

Houdini himself probably couldn’t do the magic this little can does. After replacing a R60 Mini Countryman WP, thermostat housing and cross-pipe; the cross-pipe started leaking behind the WP connection after a couple of months.

Replaced the pipe twice and same thing. The repair procedure is painful. After using this magic potion, the leak stopped. Nothing is perfect, every once in awhile (months) I might have to top up a small bit (nothing major), but beats trying to access the cross-pipe time and time again.

Had a slight leak (as in leaking half the expansion tank a week) on the water pump gasket AND the radiator on my VW Golf GTI and a bit sceptical if this stuff would work. Put it in as per instructions and had to give it a few days to circulate from the expansion tank into the system.

Glad to say since putting it in I have not lost a drop of coolant. I would recommend it for small leaks and as a preventative additive.

I own a 1997 Oldsmobile van with the 3. 4 V 6. Radiator started leaking with a few drips which then, over time, became a major leak spraying coolant when system was under pressure. I tried a few other more expensive products, none of which worked at all.

An old timer recommended this product to me with good instructions on how to add it to my coolant system. I put the tables in an empty gallon milk jug, (washing the jug first of course) and then put about half a gallon of hot water in the jug and then shaking it vigorously.

I then poured the product into the radiator, topped it off with water and started the motor and let it idle until the motor warmed up. I then shut the motor off and let it cool down. The radiator was still hissing when I turned the motor off, but in a few minutes, it stopped hissing and stopped leaking.

When the motor had cooled, I added more water, started the motor and drove around for about half an hour. No more hissing, no more leaking. This lasted about a week. I was in a drive-thru on a hot summer day and the hissing returned, but by the time I reached the pick-up window, the hissing had stopped.

This would happen periodically over the next several weeks, usually at stop lights. Each time this happened, I would check the water level in the radiator with the motor cool and add a bit more water, (I always carried several gallon jugs of water with me).

After about three months, I finally had some free time and replaced the radiator. What I discovered is that the plastic side of the radiator had several very large and long cracks running down the side and the plastic was extremely brittle, (I could literally break it apart with my fingers with hardly any effort).

Apparently, the stop leak would repair a crack allowing the system to build pressure which would then open a new crack which the product would then seal. I give this product five stars as it kept sealing cracks as they appeared, as well as the price of the product, (unlike the more expensive product which sprayed glitter all over my engine compartment).

In my situation, it bought me time as the radiator definitely needed to be replaced due to the brittle plastic, but it was well worth the five buck I spent to get me there.

For the record, these are more for leak prevention then they are for stopping leaks. These type of tablets are added to all new cars at the factory to ensure a water tight seal in the cooling system.

If you have a small, or extremely slow leak, they may be able to stop it. However, you should always add these to a cooling system in which you do a full coolant flush or hose and/or radiator replacement.

They will work in all engine types with all coolant types.

I had a tiny leak somewhere in the lower part of the cooling system that did not show up using the pressure test method of detection at the shop. My mechanic suggested trying a sealer. I purchased the 2X concentrate originally then I called the Bars Leaks tech support line for help with application.

They suggested using 3 of the tablets instead. Got some of them and used as directed. Worked to repair my leak. I recommend them now, at least, for my kind of leak.

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 left it at.

I’ve been driving it for a couple weeks now and have even gotten on it fairly hard and haven’t lost a drop of coolant yet. I’m actually in shock. We’ll see how long it holds up, and if it blows I still have 11 or 12 more ounces to try hitting it with again.

If I get a few months out of it I’ll be happy. Please note that if you have a head gasket leak on a car you really want to keep, do not use this. Bite the bullet and get it repaired properly. On the other hand, if you have a 32 year old car that you didn’t spend much on and are just using as a beater, it’s definitely worth a shot.

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 fun at me for doing so, saying that those things never work.

However, after checking the vehicle, he could not find a leak anywhere. He told me the head gasket hadn’t blown at all. The vehicle drove fine! The exhaust didn’t puff white smoke anymore nor did it smell sweet.

It has only been a couple of weeks, but it appears the leak has been sealed. I am very impressed.

OK here’s the deal. I have a 1999 Ford F250 with a clogged radiator/heater core and when towing it was always over heat when towing a heavy load (5000lbs – boat and 1800lb in bed) during summertime heat of 100F degrees.

1st cleaned radiator out with Irontite ThoroFlush which made my heater core leak like a babbling brook. Approx a pint of water would drip on passenger side floor in 5 min or LESS. So I read and decided to give K-Seal a try as replacing the heater core is a little tough but doable ( 4hr job for a DIY if you don’t break any other parts along the way).

Literally after about 5 min of pouring in K-Seal in radiator the massive dripping under the heater core started to slow down to a drip. then NOTHING. ZERO water. THIS STUFF IS AMAZING. Directions say to leave it in, no need to drain everything and refill with antifreeze so I have kept it in for now.

I’ll replace with regular antifreeze soon but if you have a leaky radiator/heater core, this is worth a try to delay costly repairs (if you don’t work on cars) like I can Hope this helps anyone deciding to give this a try, currently under $20.

So, my turbo has recently cracked on my 2019 Civic Si; leaking coolant constantly throughout the day. Very hesitant about these products in general but wanted to give it a shot for a temporary fix until my new turbo arrives.

I gave K-Seal a call (great customer service), the lady on the phone gave me an honest answer of “potentially” and explained how the product works by using heat to form the seal. That’s all I needed to hear.

She wished me the best and I pulled the trigger. Easy instructions to follow and I only needed half of the 8oz bottle. It sealed my turbo completely within 30 minutes. I didn’t believe it honestly but, I’m holding 20lbs of boost & no more leaks or having to refill my coolant every morning!! Obviously, I wouldn’t suggest this as a lifetime fix but, it WILL get your car running as long as you need it to, until you can get the proper repairs done.

I do advise to flush out your system after a few days JUST to be on the safe side.

I have an older Subaru, now has 280k miles on it all my own. About 5 years ago I used this product on a recommendation of a friend as the car was getting older and had a very small leak. It worked well and held up a long time.

Recently after taking the car to a shop to fix what they said was a leaky hose and getting a huge bill, I still had a problem and nearly overheated twice. So tried K-Seal again. The slight smell of coolant is gone, the car appears to have a bit more power and the coolant has not gone down at all since using.

I highly recommend for older cars where you are trying not to dump too much money into them. I know some people say there are risks it might bind up the radiator or other things but older cars , not much to risk.

Everyone I know including my mechanic friend has had a good experience with this product.

A number of years ago I noticed some coolant leaking from my ’91 Nissan D21 2. 4 liter pick up truck near the front of the vehicle approx. on the side of the radiator near the overflow tank. I had determine I was experiencing a head gasket leak along the intake side of the cylinder head.

This vehicle basically had 300k on it and I really did not want to, nor did I actually had the time to pull the head off. I had read about K seal and decided to give it a try. Well, that was about three or more years ago and the engine is still running just fine with no signs of leaking what so ever.

This product is “Out Of This World”!!! Thanks So Much For This Wonderful Product!! A Life Saver!!!.

Took my car to get brake pads done. Whilst parked up and engine running i noticed red coolant running into gutter as it slopes somewhat. I looked under car and coolant was dripping and it looked like everywhere.

Must be radiator or hose, even the t bar water pump under radiator which my car has these are prone to leaks also. Anyways i panicked like you do and thought ive got to go to Halfords. Car made it there although was getting hot.

I bought 2 bottles of Stop Leak. Waited a while to get coolant tank top off as it was overflowing. Got top off let pressure out slowly without getting burned and poured in 2 bottles! Let coolant drop slightly then topped it up with anti freeze, put top back on.

Left engine running with heater on full and took it for a spin. Voila! seems to have done the trick for now. Coolant temps are normal and i have warm air from vents. This stuff is great, dont know how long it will last but it works for now.

Just ensure you have coolant with you just in case.

Unfortunately I won’t be buying this again! I have a temperamental leak on my Jag a couple of times a yr and I usually buy a gold Holts which does the job. However there was no holts in stock so had to buy this.

It didn’t work after a few days so returned to store and still no holts so had to buy another bottle but still no joy! Ordered gold Holts online and fixed problem immediately!.

I had developed a small radiator leak. I don’t have the money to keep going to garages and Google told me to get a product like this one. I checked Halfords website and this came up as very good. It was also a good price.

Took it home, followed the instructions and it worked – no more leak! Quick and easy to use for us ‘car dummies’.

This actually worked in my application! My radiator was slowly leaking coolant in the middle left section. I had to refill the reservoir once a month and it was smelling hot coolant every time I got off my car.

I was doubting if this would work, but gave it a try. So far so good the coolant leaking I believe it stopped. I have had not refill my coolant reservoir anymore and no more hot coolant smell. I suggest you try this before taking the car in for repairs.

This is to the one that commented not recommended 2 years ago. I bought it a year ago and it worked. I don’t even know where it’s leaking at. But it just started leaking again so I’m going to buy some more it lasted a year so I think that’s a very good deal considering a radiator would cost me over $100.

My 21 year old vehicle sprung a small leak in the radiator. Following the instructions, I tried this powder. No more leak. Easy and very low cost repair. Since my system only holds 8 liters, I only put in 1/2 of the powder, keeping the rest for later.

Highly recommended.

This product comes in the cutest little container. I just had to mention that. Anyway, I was smelling a little coolant from car overtime and was noticing a slow decrease in the reservoir, which I first thought was condensation, from cold temps.

Although, I hadn’t really noticed that before. you know how sometimes you want to make yourself think something is one thing to avoid acknowledging and maybe another. lol. I turned out to be an extremely slow coolant leak.

I poured about 8 oz of the 11 oz of this product in the reservoir and a couple of days, the slight cool sent was no longer there and that drip under ceased.

Used on Ford truck to seal leaking heater core. Used on a Dodge neon to seal leaking head gasket and possibly cracked head until they could get fixed. Used on my 1987 Toyota 4runner 4×4 to fix leaking radiator,it worked almost instantly and it lasted until i could order a new all aluminum radiator.

This continues to be my go to product for any type of cooling system /gasket leaks andand my friends use this product also after i showed them how great it works. Learned about this product by watching automotive shows on velocity channel.

Product was designed for the racing industry, now available to the public.

I have owned an outdoor wood burning furnace for more than five years. I love the engineering. However, I was talked into buying “an upgrade” stainless steel “never rust” boiler. Don’t do it. What I received was a 409 SS ferritic steel that is the lowest grade of SS and corrodes with a passion.

However, it is very difficult for the average welder to weld it so it won’t leak. Combine the corrosion issue (worse than mild steel) and lack of being able to weld it to patch the leaks and you have an expensive paperweight.

Thanksfully, I have used Hercules Boiler Liquid for several years and it absolutely works without plugging up the rest of the system or interfering with the heat exchangers. The price is right, the shipping is fast, and it works, you can’t beat it.

cast iron had exploded , crack and pinholes…. nobody believed this liquid could work but it completely sealed the cracks… i did follow directions carefully , keeping everything hot etc…

After attempting an easy pipe repair, my 30 yr old boiler sprung a leak. Chased the leak for 2 weeks, and filled the boiler every day. Found this product online and was skeptical at first, but it was a wise choice to try it instead of replacing the boiler.

It worked in one day, and sealed everything fast. I was shocked at how fast it worked !!!.

Purchased this after going through You Tube University looking for a slow radiator coolant slowly disappearing Fix. Found this particular Bars product that allows to be used without flushing radiator.

Shake well install on a cold engine, let run for 15 to 20 minutes idling. In my opinion it wasn’t until I drove it the next time for almost an hour did it work fully. The metal particles find the small leaks and plug the holes.

I did find one leak at the plastic side part seem of the radiator that was weeping at the bottom near but not at the drain plug but seem. Radiator $175 plus labor or $12 becomes a no brainer. This stuff worked.

About a year ago I had a pretty decent leak in my radiator and had to fill my jeep with coolant anytime I hit the highway. Well I decided to use this product and it worked surprisingly. HOWEVER, if you do not flush it out within 8 months it will grow into a sludge that completely clogs up the system and will not let the coolant move properly through it.

DO NOT USE THIS PRODUCT UNLESS YOU PLAN TO FLUSH THE SYSTEM!.

My older Satarn was running hot, obviously leaking water from Raditor. The heater would quit working and it was deathly cold. I was working part time and did not have any money for costly repairs, especially given the fact it was an older car.

I was scared that I would break down somewhere though, and me being a female was really worried about that, and also worried that by running my card with it running hot it may blow the engine. I found this product online and it was pretty cost effective, so I gave it a try.

Directions were very easy to follow, even for me, whom doesn’t know much about cars. It worked like a charm, never had any more problems with leaking and my car did’t run hot again. It saved me tons of money I didn’t have for a costly repair from a mechanic.

It was a God Send and I would highly recommend this product.

I tried with my Mitsubishi Galant Car. I followed the given guidelines as per the pack. But did not work it for me.

does what it says on the tin, brilliant

Perfect

I had a major leak of coolant happening in my little old suv. Every day I’d have to check and refill coolant. Eventually I decided that I may aswell try this stuff but really expected nothing. With the major leak my system had basically been flushed multiple times already so I just dumped the whole bottle of sealant straight into radiator (not the clear overfill container but metal cap to rad) and then added the coolant.

Ran my SUV for 10 minutes with the heat on high (heard that can help?), topped off with a touch more coolant, ran it again for 10 minutes and haven’t had an issue since then. It’s only been 1 week since used so will update if things change but was worth the $$ for me.

I put the whole bottle of this product into my 1999 Ford F150 XL on a cold engine & started her up. As usual the leak started again very heavy & I doubted very much whether this stuff would work as the leak was just pouring out of her quite badly.

It was still going a half hour later & I thought there was no way this was going to work. Then about 5 minutes after that it started to show some signs of slowing down a little. Five minutes more & it slowed to an occasional drip & then stopped dripping completely.

I then drove the truck a few blocks & checked it again, letting it idle another 20 minutes & continued monitoring it. Well it seems to have worked & I have no more leaks. Seams to be holding so only time will tell.

Had a coolant leak on a semi under the cab near the back of engine. Couldn’t reach the part that was leaking not even through the dog door on the top of tranny but two bottles of this stop leak sealed up my leak for me.

Took a day or two to stop seeing the coolant leak. This truck was leaking coolant for a year before i added this to it.

I Bought this for a rusted out weld around 3/4 of the nozzle of the gas tank of my 2003 mitsubishi lancer (Evap Code). I removed the tank, wire brushed as much rust as i could, washed with alcohol then followed the directions.

Mixed it, pushed it into the crack, built a barrier around the nozzle. The next step i think is very very important, wait at least 24 Hrs before painting or weatherizing even longer if possible. I think this is where I went wrong with a different product I tried.

Either way after 15 or so Hrs it still seemed a tad pliable after 24 Hrs it was hard as a rock. I waited another 1/2 day then painted & reinstalled. after 300 miles still no evap code. I got my fingers crossed & will update this review later if possible.

Bought this product to repair a punctured fuel tank in my lawn mower’s plastic fuel tank. Have had no issues ever since doing the repairs. I would suggest using gloves when applying the putty.

This putty melts in gas. It is absolute garbage. it appears to work for about 2 hours and then it softens when exposed to gasoline. on a gas tank. do not buy this garbage, pop for the j+b weld steel stik putty.

much faster, effective (as in, it actually works), and is a permanent fix.

My 2005 Jeep Grand Cherokee, 5. 7 Hemi engine, developed a radiator leak, which required adding a quart of cooling fluid every 4 days. It is a major job to replace the radiator. I added the K&W stop leak to the existing coolant and the leak stopped, within 1/2 hour’s driving time.

I waited 2 days and then flushed the entire cooling system and installed new coolant. The flush was NOT REQUIRED, but my antifreeze level was very low. Still NO leak after flushing system. I have tried many other such products over the years, but this product is the BEST!.

The product fix a coolant leak at my water pump. But if you put incorrect amount of the product your car can overheat in some point after the use. I correct my mistake just flushing the coolant system and the car temp get back to normal and with no leaks !.

Bought this product about a few weeks ago, after i just replace the lifters. Notice a small slow dripping from the headers gasket. Retorque the bolts and coolant was still dripping. Decide to buy the K&W product and give it a try, and it work so far.

Just FYI,(my experience) i needed to flush the heater core, engine was getting hot and the heater core was clogged up with the product substance. Flushed the heater core, and unclogged it (It might need another flush).

I give it a thumbs up.

My car suddenly decided to start overheating one night. I checked the radiator and could see coolant in the engine bay. I couldn’t find the leak though. The next day I put this in and it worked. After a few minutes of putting in, my engine temp stabilized while driving around.

I opened the hood and there was no coolant around. We’ll see how long it will hold up.

Coolant had been just pouring out of the bottom of my car, I was worried it might be done for good or that this would cost thousands of dollars in servicing to fix. I poured this tiny bottle of solution (around $5-6) into my radiator, drove to work, and when I got out 7 hours later, I absolutely couldn’t believe that there wasn’t a single drop of coolant under my car.

Literally magic.

The radiator in my 1989 F-150 appeared to have been beaten with a ball pein hammer for the last 23 years. It had a small leak from somewhere (driverside on radiator), and would slowly leak ~3/8 of the coolant out over a day.

After doing research on all of the radiator sealers, alumiseal appears to be the least harsh on the cooling system. I put about 80% of the bottle directly into the radiator and within 10 miles there was no leak.

If you have a beater that you dont want to spend $$$ on/ dont have time to put in a new radiator, THIS IS PERFECT.

I have used this product to stop coolant leaks in several vehicles one of them being quite a bad leake loosing about a litre on a seven mile drive also leaked when parked the leak was easily visible my local garage diagnosed a head gasket failure the seal held for 45000 miles when I sold the vehicle still not leaking, this product really does do what it says on the bottle.

This is a brilliant product, well recommended.

Been using for years, best product of it’s type had to search it out because local parts store doesn’t sell it anymore.

It did nothing for the block crack in my old car. I followed the directions exactly, lead didn’t even slow down.

TranslateShow in original languageFrher war Wynns groe Klasse, war eine milchige Flssigkeit mit kleinen Schwebeteilchen. Jetzt wie die meisten neueren, bringt es nichts. Im Extremfall verstopfen die Khlerlamellen.

TranslateShow in original languageAn meinem 207 verschwand ber die Woche gesehen ein viertel Liter Khlflssigkeit ohne dass ich eine Undichtigkeit entdecken konnte. Nach einfllen von Wynns Khlerdichtung nach Gebrauchsanleitung ist das System wieder dicht.

Super.

TranslateShow in original languageDit product doet wat het zegt; ik had een lekje in mijn radiator en nu niet meer. Het is wel de tweede keer dat ik dit gekocht heb in ongeveer 20. 000 km, dus het is zeker geen definitieve oplossing.