14 best head gasket sealer

Head gasket sealer is a product designed to address issues with a vehicle's head gasket, which is a critical component in the engine that seals the combustion chambers and prevents coolant and oil from mixing. When a head gasket fails, it can lead to several problems, including overheating, loss of engine power, and coolant/oil contamination. Head gasket sealers are used as a temporary or emergency solution to fix minor head gasket leaks without the need for expensive and time-consuming engine repairs.

Here are some key points about head gasket sealer:

  1. Sealing Mechanism: Head gasket sealers work by forming a temporary seal around the damaged area of the head gasket. They typically contain chemical compounds that can bond with the gasket material and fill small cracks or gaps.

  2. Temporary Solution: Head gasket sealers are not a permanent fix for a damaged head gasket. They are meant to provide a short-term solution to get a vehicle back on the road temporarily. A proper repair, such as replacing the head gasket, is necessary for a long-term fix.

  3. Types: There are different types of head gasket sealers, including liquid sealers that are poured into the radiator or coolant reservoir and tablet or pellet-based sealers that are added directly to the cooling system.The choice of product depends on the specific needs of the vehicle.

  4. Usage: To use a head gasket sealer, the coolant system should be drained, and the sealer is added as per the product's instructions. After adding the sealer, the engine is typically run to allow the product to circulate and seal the gasket leak. It's important to follow the manufacturer's guidelines carefully.

  5. Effectiveness: The effectiveness of head gasket sealers can vary depending on the extent of the damage to the gasket and the quality of the product. In some cases, they may provide a temporary solution, allowing the vehicle to be driven for a limited time. However, they may not work for severe head gasket failures.

  6. Precautions: While head gasket sealers can be a convenient option for minor issues, they are not a substitute for proper repairs. It's important to address the underlying problem by fixing or replacing the head gasket as soon as possible to prevent further engine damage.

  7. Consultation: If you suspect a head gasket issue with your vehicle, it's advisable to consult a qualified mechanic or automotive professional. They can diagnose the problem accurately and recommend the best course of action, which may include using a head gasket sealer or performing more extensive repairs.

In summary, head gasket sealers are products designed to temporarily address minor head gasket leaks in vehicles. They are not a long-term solution and should be used as a stopgap measure while planning for proper head gasket repair or replacement.

Below you can find our editor's choice of the best head gasket sealer on the market
  

Bar's Leak HG-1 HEAD SEAL Blown Head Gasket Repair

Bar's Leaks

Based on 1 reviews Check latest price

Product description

Bar's Leaks Head Gasket and Cooling Sealant repairs blown head and intake gasket leaks. Seals cracked cylinder heads and blocks. Stops heater core and radiator leaks. Fixes leaking freeze and core plugs.

  • Repairs blown head and intake gasket leaks
  • Seals cracked cylinder heads and blocks
  • Stops heater core and radiator leaks
  • Fixes leaking freeze and core plugs

User questions & answers

Question: Do I have to keep using it or is it a one and done type of deal
Answer: It worked for me. 2005 impala v6. One bottle saved it from the crusher. Mechanics want 2000$usd for the replacement of head gaskets. The car ran badly for a while and still used some water but after a few drives it works fine. The check engine light even finally turned off. It was worth the price even just to avoid towing this again, but it keeps running!
Question: will it plug the heater core
Answer: I have a 1995 Honda Odyssey, 4 cylinders. Blown head gasket, puffs of steam out the tailpipe, small geyser from the radiator. Used Blue Devil, following all instructions, and about 80% better but still some steam out the tailpipe and smaller bubbles in the coolant. As per tech advice from Blue Devil I took out the spark plug from the offending chamber and ran for 50 minutes. I did this aggravation twice. Still leak. So I got this product, flushed the system using Prestone chemical flush, keep the thermostat out and then put in the Ba's Leak HG-1. I only used bout 40% of the bottle and diluted it about 3:1 with distilled water and antifreeze. Did this because it was so thick. Followed instructions, initial run was difficult because it was not circulating well and was running hot. But the second session went fine after top off. After the fourth cycle I looked into the running radiator and there were no more bubbles and no more steam out the back. Success! However, my heater core is clogged. No big deal as this is California. Question: can I eventually restore the heater core by back flushing the cooling system? I wouldn't do this till the Fall. In the past K Seal had pugged up my heater core and I recoverd most of the function by back flushing (Firestone, $120).
Question: Ok for ford 6.9 idi diesel ?Eng overheated-very slight combustion leak in cooling sys,no white smoke,oil clean. Is1 bottle enough for eng 8gal cap
Answer: yes also try engine restore to stop your combustion leak it works well with 6.9 idi my blow by was so bad it blew off the oil cap once but after engine restore 8 cylinder it actually brought the compression backup to factory only drawback is you must use it every oil change
Question: will this mix with other stop leak
Answer: I am not sure, but I would call Bar's Leak Tech Service at Call tech support:800-345-6572 (M-F, 8a -5p EST) You can also go to their site Bar's Leak.com and lookn at their FAQ section

Product features

Blown Head Gasket?

When you think about a blown head gasket, do you see your money being spent at the repair shop? How much time and inconvenience is involved in taking your car to a mechanic for blown head gasket repair? The lost time is a frustration, and the money it takes to alleviate a head gasket leak is overwhelming. That’s because fixing a head gasket can cost you quite a bit (typically $1,500-$3,000). We know you would rather spend that money on the things that matter most. That’s why we created professional-grade, easy-to-use head gasket solutions. It’ll repair your leaking head gasket and save you money.

Bar’s Leaks recommends asking a few questions to narrow the field.

Bar’s Leaks is more than just a stop-leak company

We are a team of enthusiasts and experts who create memorable experiences with each and every one of our customers. With nearly 70 years of experience in helping everyday automobile owners repair leaks, we have the track record of success and long history that demonstrates our commitment and passion to helping drivers of all experience levels. You’ll see that our passion shines through in everything we do.

Each individual Bar’s Leaks product is formulated and manufactured right here in the U.S.A. We’re committed to creating fast and affordable products that fit perfectly into your lifestyle and budget. Choose Bar’s Leaks, so you can discover just how simple automotive maintenance can be when you have the right tools.

Bar’s Leaks. The fastest, safest way to get your show back on the road. Guaranteed.

Bar's Leaks 1111 Block Seal Permanent Head Gasket Fix 24 oz.

Bar's Leaks

Based on 760 reviews Check latest price

Product description

If the words “blown head gasket” make you nervous, we’re right there with you. We know firsthand that fixing a blown head gasket requires a hefty chunk of change and a few days without your car. Who has time to spend taking their car to the shop for a blown head gasket? And who has the extra cash to pay for a blown head gasket without planning for it? No, visiting the shop for a blown head gasket fix isn’t ideal. But what if we told you it was possible to fix this yourself with one of the most reliable blown head gasket solutions on the planet? Our easy-to-use Bar’s Leaks Head Gasket Fix will not only save you all that cash, but also get you back on the road in less than an hour. At Bar’s Leaks, we specialize in creating chemical repair solutions that are fast, easy, effective and affordable. Rather than spending hundreds or thousands of dollars at the repair shop, you spend just a few dollars and all without any of the inconvenience. This product contains a combination of antifreeze-compatible sodium silicate sealing liquid and various gasket-sealing particles that penetrate gaps and cracks and harden to permanently stop leaks. It’s liquid technology for damaged, leaking or blown head gaskets, and with over two million bottles sold, you can count on it to perform. We have a team of top-flight chemical engineers who are always innovating and pursuing ways to improve our existing products. As auto manufacturers introduce new technologies, we offer new products that will help everyday drivers save time and money through fast and effective solutions. Using our head gasket repair liquid is easy. Simply follow along with Bobby and Caitlin in our how-to video to safely and quickly get your car back on the road. There’s no reason a blown head gasket should sideline your life.

  • Stops block leaks
  • Seals cracked cylinder heads and blocks
  • Repairs blown head gaskets
  • Contains a combination of antifreeze compatible sodium silicate sealing liquid and various size gasket sealing particles which penetrate gaps & cracks and harden to permanently stop leaks.

User questions & answers

Question: can i use it when the copper stuff failed to work
Answer: What I did was dump a can of the head gasket fix, _and_ a can of the copper stuff into the radiator. I think they're pretty much the same, except the head gasket stuff has bigger particles. My reasoning was that I have no idea what the leak(s?) look like, and multiple particle sizes were better than not. At any rate - one can of each into my 1999 Ranger 3.0 appears to have stopped a leak that was occurring between the timing cover and the block. On that engine, the timing cover has ports for the water pump, and taking off the timing cover.... pulley, A/C components, P/S components, water pump, and alternator, as well as the radiator. A real pain in winky. I figured before all that work... lets give 'er a try with Bar's. So far so good!
Question: Can thsi item ship to malaysia
Answer: You may try putting it in your shipping cart. if it shows a warning sign about the shipping problem then it won't be shipped there.
Question: Can this seal leak from pistons to coolant system, rather than vice-versa? My car doesn't burn coolant, rather the exhaust goes into coolant system
Answer: Yes. A bad head gasket can cause water to get into the oil (very very bad), water into the combustion chamber (white clouds from the exhaust pipes) and other less than desirable things. The leak seal product is a stop-gap measure not a long term fix. The head gasket needs to be changed.
Question: If my car continues to emit white smoke from exhaust, should i switch to HG-1 instead
Answer: Typically, the seal is formed during the recommended idle time shown in the instructions, but if the leak is more severe or harder to get to, it could take several thermal cycles (heating up and cooling down) before the leak is fully sealed. In addition to watching for the white smoke to go away, our recommendation is to continue to monitor the engine temperature and coolant level over the next couple of days to see if the vehicle is overheating, and also to note how much coolant you are adding, as well as how often you are adding it. If the leak is not sealed, and you wish to use HG-1, you certainly could do so, but we would recommend that you drain and flush the cooling system before you do so in order to prevent the formation of a flow restriction from having too much stop leak product in your vehicle's coolant at one time.If you have any additional questions, or need additional information, please call our Tech Support team at 1-800-345-6572. We are available to help you Monday through Friday, from 8 am to 5 pm Eastern time.

Product features

Blown Head Gasket?

When you think about a blown head gasket, do you see your money being spent at the repair shop? How much time and inconvenience is involved in taking your car to a mechanic for blown head gasket repair? The lost time is a frustration, and the money it takes to alleviate a head gasket leak is overwhelming. That’s because fixing a head gasket can cost you quite a bit (typically $1,500-$3,000). We know you would rather spend that money on the things that matter most. That’s why we created professional-grade, easy-to-use head gasket solutions. It’ll repair your leaking head gasket and save you money.

Bar’s Leaks recommends asking a few questions to narrow the field.

Bar’s Leaks is more than just a stop-leak company

We are a team of enthusiasts and experts who create memorable experiences with each and every one of our customers. With nearly 70 years of experience in helping everyday automobile owners repair leaks, we have the track record of success and long history that demonstrates our commitment and passion to helping drivers of all experience levels. You’ll see that our passion shines through in everything we do.

Each individual Bar’s Leaks product is formulated and manufactured right here in the U.S.A. We’re committed to creating fast and affordable products that fit perfectly into your lifestyle and budget. Choose Bar’s Leaks, so you can discover just how simple automotive maintenance can be when you have the right tools.

Bar’s Leaks. The fastest, safest way to get your show back on the road. Guaranteed.

K-SEAL Ultimate Permanent Head Gasket Repair ST3501 16oz Multi-Purpose Formula Stop Leaks in the Head Gasket, Cracked/Porous Blocks, Radiator & Heater Core. A True Pour & Go, Trade Trusted Stop Leak

K-Seal

Based on 391 reviews Check latest price

Product description

K-Seal ULTIMATE is the simple, permanent fix for blown head gaskets, cracked heads and blocks, and porous engine blocks. Our unique formula works with all water-cooled engines – there’s no need to drain or flush your cooling system, and it doesn’t matter what kind of antifreeze or coolant you’ve used previously. Simply shake the bottle, pour K-Seal ULTIMATE into your cooling system, and you’re back on the road. Just one bottle of K-Seal ULTIMATE is enough to fix blown head gaskets and cracked heads in cars, SUVs and small trucks. For larger engines, simply use two bottles.

  • REPAIRS IN MINUTES: Permanently fix blown head gaskets, cracked heads and cracked/porous blocks including aluminum heads in old and new cars. The only head gasket and block sealant that is 3rd party tested to meet ASTM D3147. Save time/money
  • SEALS CRACKS AND STOPS LEAKS: A DIY alternative to costly repairs, our head gasket fix permanently seals cracks and holes! Quickly repair your blocks, leaking radiator, freeze plug, heater core and water pump casing with no adverse impact on efficiency.
  • POUR AND GO: Our head gasket sealer is easy to use just shake, add to your radiator/overflow and run the engine! Unlike some competitive products, it mixes with all types of antifreeze, absolutely no draining, flushing or pulling the thermostat required.
  • SCIENTIFICALLY TESTED: Safe, effective, our head gasket and block repair seals leaks up to 1/32 of an inch! Once cured, the repair withstands the high pressure of the combustion chamber, all without failing or clogging the cooling system. US Bestseller
  • CUSTOMER SUPPORT: If our head gasket repair leak doesn’t seal your intake gasket, the system might be over-pressurized. Check the Technical Specification section of this page for extra instructions for a successful repair. Over 8 million bottles sold.

User questions & answers

Question: what if car won't start
Answer: Has to recirculate through the cooling system. Car has to be running. I can't see any other way around that.
Question: Does it use Sodium Silicate
Answer: Nowhere on the bottle does it say sodium silicate.
Question: Is this any different from the smaller pour and go? I have already put that in the engine. If it does not work, can I add this
Answer: I use this in antifreeze for a head leak Did work for some tine
Question: Is it okay to continue to idle the car with engine and brake lights on with liquid coming out of radiator? It says to idle for 20 minutes
Answer: The system should be sealed as the product circulates though it for the 20 minutes.

Product features

Permanent Coolant Leak Repair with K-Seal

Coolant leaks don’t have to result in costly repair bills – simply add K-Seal to your coolant system for a quick and permanent fix. K-Seal is scientifically tested, trusted by millions of customers worldwide, and the only coolant leak repair fluid carried by the AA, the UK’s largest roadside repair company.

K-Seal couldn’t be simpler to use. K-Seal’s unique formula will seek out holes and cracks, and permanently seal them, with no adverse impact on the efficiency of your engine cooling.

No Need for Expensive Head Gasket Repairs

K-Seal ULTIMATE K3501 Head Gasket Repair is the simple, permanent fix for blown head gaskets, cracked heads and blocks, and porous engine blocks.

Our unique formula works with all water-cooled engines – there’s no need to drain or flush your cooling system, and it doesn’t matter what kind of antifreeze or coolant you’ve used previously. Simply shake the bottle, pour K-Seal ULTIMATE into your cooling system, and you’re back on the road.

Common Coolant Leaks

K-Seal can deal with all of these leaks and more, as long as they are identified as early as possible. It is easy to use – simply shake it and pour it into the coolant mixture and it will work automatically.

Steel Seal Blown Head Gasket Fix Repair Sealer - 6 Cylinder

Based on 173 reviews Check latest price

Product description

Steel Seal Head Gasket Sealer permanetly repairs blown head gasket leaks, cracked heads, heater cores and freeze plugs. Easy to use for the Do-It-Yourself repair. Single repair for 6 cylinder engines

  • Permanently seals a crack in the head gasket
  • Do-It-Yourself Pour in Head Gasket Fix
  • Used by thousands of repair shops nationwide
  • Backed with a 100% Money-Back Guarantee
  • Used for 6 Cylinder Engines

User questions & answers

Question: How about4 cylinder Diesel
Answer: Yes our product will work with 4 cylinder diesel engines.
Question: Bought couple months ago worked 6cyl for 8cyl same bottle may need another bottle
Answer: Flush with water, remove the thermostat and add 2 bottles for 6 or 8 cylinder. It will work. Change plugs and oil afterwards.
Question: If the coolant is at max level, do you remove 16 oz then pour this in
Answer: Yes remove 16 oz then pour in you dont want to over fill. Depending on how much you drive the stuff works on the first couple of trips. It worked on my nissan
Question: I have a 1998 buick lesabre that has a whole lot of white smoke comming out the back, would this work in my case or is it too far gone
Answer: I put it in a 1995 Neon that was over heating and had white smoke and it fixed it. I drove it for nearly 4 years after the treatment. I believe it works but the only way to know for sure is to try it. I wouldn't hesitate to try it again. It worked great for me. Best of luck!

BlueDevil Head Gasket Sealer (38386)

BlueDevil Products

Based on 1 reviews Check latest price

Product description

BlueDevil Head Gasket Sealer is your head gasket repair solution as it will repair and seal leaks in blown head gaskets, warped or cracked heads, heater cores, and freeze plugs. BlueDevil contains no solid or particulate matter and will not clog or harm your engine. It bonds to metal, aluminum, cast, alloy, or plastic, and it’s safe and easy to use as a permanent seal for your head gasket leak. BlueDevil Head Gasket Sealer is compatible in gasoline and diesel engines.

  • Good for Head Gaskets, Warped or Cracked Heads, Heater Cores, and Freeze Plugs
  • Contains no solid or particulate matter that can harm a vehicles engine
  • Alternative solution for costly and time consuming repairs
  • Safe and easy to use
  • Permanent Repair

User questions & answers

Question: I don't get the "remove thermostat" part. If i remove my thermostat where am i going to plug the hose into? Does it mean to replace it with a new one
Answer: Most thermostats can be removed without causing a leak. I am guessing that yours might be like my truck where the gasket is incorporated into the thermostat. If so, you can probably adjust the time to allow the thermostat to open and replace it afterward. I cut the guts out of mine but it was probably overkill.
Question: If i just replaced my thermostat do i need to remove it, it's such a pia
Answer: Yes. For a "perfect" flush, the thermostat needs removed. Pain as it is, it's a good time to replace it.
Question: How do I return the product if I have already used it
Answer: You can't.
Question: Im getting combustion in my radiator,not coolant in oil,will it work
Answer: had same problem and it didn't work

K&W 401224 FiberLock Head Gasket & Block Repair - 32 Fl Oz

K&W

Based on 463 reviews Check latest price

Product description

Permanent pour 'n go head gasket & block repair compatible with all types of antifreeze. Repairs cooling system leaks w/3 unique technologies: military-strength fibers nanotechnology & Cool-X Conditioner-the ultimate solution for all coolant leaks.

  • Easy Pour and Go Formula!
  • Permanently fixes head gaskets, engine blocks, cooling systems, and cylinder heads.
  • "Contains 3 unique technologies. Military-Strength Fibers create multi-layer repair over cracks with a web-like weave. Nanotechnology permanently fixes the smallest cracks and crevices. Cool-X Conditioner – lowers operating temperature as it circulates through cooling system."
  • Seals larger holes with less fluid loss than competitive products as proven by lab test (ASTM D6107)
  • Works with all antifreeze or plain water.

User questions & answers

Question: My 01 Civic only took 1/2 of the mixture (1qt sealant + 3qt water), even after burping - it took no more. Is this OK
Answer: run it
Question: how clean it
Answer: I wish to know that. I suggest all headache should go to the manufacturer because she did make function test except it does 'block the leaking'. I believe she does not know how to prevent the block of the coolant level sensor; how to prevent the trigger of high temperature warning from the temperature sensor of the engine...etc.
Question: is there a limit to size of leak
Answer: I had a small leak on the head gasket it sealed it fine I believe it would seal a larger leak, be sure to take your thermostat out and flush the cooling system at least four times follow the directions on the bottle.
Question: How do I clean this crap out of my radiator? Followed directions and now my head gasket doesn't leak but my radiator is totally clogged. Rad was new
Answer: It’s a 32 ounce bottle. If you’re putting it in a car you should only use 10 ounces. I wonder if you didn’t use a whole bottle, perhaps? I added a whole bottle to my Kenworth and my problem was solved. I had a Radiator seam leak in a plastic/aluminum radiator

Product features

MILITARY STRENGTH FIBERS

Contains sodium silicate reinforced with military-strength proprietary fibers with a high strength-to-weight ratio. The fibers form an interlocking web-like weave over the crack or breach ensuring a permanent, multi-layer, impenetrable repair.

NANOTECHNOLOGY

Features nanoparticles so small they reach into cracks and crevices other products can't. This makes the molecular bond of the repair stronger and more solid when permanently hardened to the surface area.

COOL-X CONDITIONER

Cool-X Conditioner circulates in the cooling system for lower operating temperatures and improved heat transfer long after the repair is made.

HOW TO USE

K&W FIBERLOCK is compatible with all antifreeze or plain water (generally for racing applications). Shake bottle vigorously for 30 seconds, pour directly into the radiator, turn heater on high and idle engine for 15 minutes. You're ready to drive. FIBERLOCK will form a permanent repair over time. Read label for complete instructions.

Bar's Leaks 1100 Head Gasket Repair - 20 oz.

Bar's Leaks

Based on 227 reviews Check latest price

Product description

Suddenly noticing your temperature gauge spring towards the high end is not the best way to start your day. School, work, errands — your daily routine should not be compromised due to head gasket problems. When you experience this problem, you probably think about the time and money that will be spent in search of a block seal solution. But there’s good news: a cracked head sealant doesn’t have to be expensive or time-consuming. Our Bar’s Leaks Head Gasket Repair is scientifically formulated to permanently seal coolant leaks that are the cause of most overheating problems. It’s easy to apply, and it’s available at only a fraction of the cost of getting the same block seal fix from a mechanic. How does the need for cracked head sealant come up in the first place? Usually by overheating, which can be caused by a blown head gasket, cracked head or a leaking block. Bar’s Leaks Head Gasket Repair eliminates this problem — . This product contains a blend of aramid and refractory fibers, which provide the strength of a bulletproof vest and the heat resistance of fireproof clothing. As these particles penetrate a crack or the blown head gasket area, they lock together and bond, forming a hard, permanent ceramic-type seal. At Bar’s Leaks, we employ a team of top-flight chemical engineers who specialize in solutions such as these. Each product, our cracked head sealant included, is custom-designed to be effective, affordable and easy to install. You don’t need any special automotive expertise — you just need to be able to pop and lift your hood. The rest is about as simple as any car maintenance can be. Forget that repair bill. Simply use this product and get back on the road and back to your daily routine in no time — with several hundred extra dollars in your pocket.

  • Stops block leaks
  • Seals cracked cylinder heads and blocks
  • Repairs blown head gaskets
  • Dual Action 2 Part Formula — LIQUID CERAMIC: Liquid penetrates large and small leaks to form a seal actually harder than the original head gasket — REINFORCED FIBERS: Fiber additives lock together with liquid to increase strength and promote a permanent seal
  • Head Gasket Sealant is NOT COMPATIBLE with antifreeze and must only be added to the cooling system after ALL ANTIFREEZE has been flushed and removed.
  • Included components: Unit, Instruction Guide

User questions & answers

Question: this product can fix a crack in the engine block of a car
Answer: I got mine recently and it has bamboo only above the glass edge on top. The insert near the liquid is not bamboo. Mine stands almost 11 inches tall when the straw is in and it is 3 inches in diameter.
Question: Will this help with exhaust smoke my car smokes a lot at first starting and when I pull a steep hill
Answer: I purchased boba-sized glass pyrex straws (Hiware Glass Smoothie Straws 1/2" Extra Wide X 10" Long) to use with this, and they don't work well at all, sadly. They are SO tight that you can barely get one inserted, and because of absolutely no extra space for air to get in or out, the suction doesn't work. Really bummed because I would much prefer to use a glass straw than plastic! (Regular glass straws are too short. You could use them if they dangle two inches above the bottom of the glass, but not ideal at all. Prefer the plastic straw to that.)
Question: should I remove the old coolant before using this product
Answer: Sixty
Question: How do I get it into my radiator that does not have a cap but only a reserve for the overflow
Answer: Yes

Product features

Blown Head Gasket?

When you think about a blown head gasket, do you see your money being spent at the repair shop? The lost time is a frustration, and the money it takes to alleviate a head gasket leak is overwhelming. That’s because fixing a head gasket can cost you quite a bit. We know you would rather spend that money on the things that matter most.

Bar’s Leaks recommends asking a few questions to narrow the field.

Bar’s Leaks is more than just a stop-leak company

We are a team of enthusiasts and experts who create memorable experiences with each and every one of our customers. With nearly 70 years of experience in helping everyday automobile owners repair leaks, we have the track record of success and long history that demonstrates our commitment and passion to helping drivers of all experience levels. You’ll see that our passion shines through in everything we do.

K-SEAL Coolant Leak Repair ST5516 Heavy Duty 16oz, Multi-Purpose Formula for Truck/Tractor Coolant Leaks in the Radiator, Head Gasket, Water Pump Casing & Heater Core, A True Pour & Go -Trade Trusted

K-Seal

Based on 524 reviews Check latest price

Product description

K-Seal 8 fluid ounce bottle is effective to 20 quarts cooling capacity. Just shake, pour and go. It repairs leaks and cracks in radiator, head gasket, heater core, freeze plugs, water pump casing, cylinder heads and engine blocks. For truck, tractor, industrial, RV and large capacity engines.

  • REPAIRS IN MINUTES: Create a permanent weld within the entire coolant system, including on hard plastic radiators and aluminum heads and blocks in larger capacity engines, AG, RV etc. The only industrial coolant sealant university tested to meet ASTM D3147.
  • SEALS CRACKS AND STOPS LEAKS: Avoid expensive downtime, our coolant stop leak will permanently seal cracks and holes! Quickly repair your head gasket, block, leaking radiator, freeze plug, heater core & water pump casing with no adverse impact on efficiency.
  • POUR AND GO: Our cooling system sealer is easy to use just shake the bottle, add to your radiator/overflow and run the engine! Unlike some competitive products, it mixes with all types of antifreeze, no draining, flushing or pulling the thermostat required.
  • SCIENTIFICALLY TESTED: Safe and effective, our Heavy Duty Coolant stop leak repair seals leaks up to 1/32 of an inch! Once cured, it withstands the high pressure of the combustion chamber, without failing or clogging the cooling system. US Bestseller
  • CUSTOMER SUPPORT: If our engine coolant leak doesn’t seal your head gasket, the system might be over-pressurized. Check the Technical Specification section of this page for extra instructions for a successful repair. Over 8 million bottles sold. Save time/money

User questions & answers

Question: Tried using alumaseal, which isn't working. will i need to flush the system before using the k-seal
Answer: I used the HD Truck bottle on my 1998 GEO Tracker ( used 1/3 of the bottle ) of K-Seal and it worked. I have used so many to no avail. To answer your question, I must have @ least 3 to 4 other sealers in my colling system when I added K-Seal. It's been almost a year & no adverse effects having not flushed my radiator. Should I have flushed the radiator & the system? Yes, I should have.
Question: Will this work with aluminum heads
Answer: It works equally well with cast iron or aluminum. Great Stuff. Not a long-term solution, but it will buy you a lot of time.
Question: how much do i need to pour in a diesel 1 ton cummins
Answer: You need this one bottle for a Dodge 3500 hd. I have this one bottle in my HD Freightliner 330hp MBZ engine hauling freight (54,000 lbs cap) 6 days a week and it stopped my coolant leak in the engine bay and heater core with no blockage and no. My opinion, Many reviews say products dont work BECAUSE most people dont take care of their equipment and their vehicles are old, high mileage and no maintenance done. None of the add to a tank products are as good as replacing with new parts but thats expensive, we get it. This may or may not fix your problem but its a low cost gamble with a high probability of success. Dont listen to the negative reviews. If the problem comes back, your damage was too far gone and in need of replacement anyway.
Question: Does it work on potentially warped heads
Answer: Probably not, but read on, and learn about all coolant leak problems if you want and how effective this product is....This bottle is enough for up to 12 cylinder engines.This will work for any type of coolant leak, if the leak is small. This will work on head gasket leaks also, read this 3 minute read on what to do if its a head gasket leak. Also, for for your information - This is "liquid glass" that dries rock hard and will seal your head gasket leak (its been used in farm equipment for over 75 years and is WELL proven to work, and it was discovered over a hundred years ago), but you MUST perform a simple test. Okay, start your vehicle, let it idle for 45 minutes straight. If the temperature gauge does not indicate that your engine is overheating, then this product will most likely work. No overheating at an idle for 45 minutes MEANS that the head gasket leak is still small enough to be filled by this liquid glass. Shake the container for 30 seconds, put the liquid in your COOLANT system, drive for an hour (or other words, operate at normal temperature, especially if its an aluminum block with cast iron heads), and then let it sit for 24-48 hours (the longest time is better). This sitting time allows the liquid glass to harden completely through. If it overheats then, it most likely its a thermostat or water pump or heater core or lower radiator hose sucking shut under load (sometimes the upper one also) or radiator or radiator fan or leaking core plug or leaking coolant storage unit OR your ENGINE OIL is very low from leaking (completely different problem that has nothing to do with the coolant system, but much to do with the cooling of the engine also) or heat indicator gauge or it still could be a blown head gasket, because the hole is just too big for the sealant to seal it up OR the head gasket BLOWS in another area after you have sealed up the first hole with the coolant sealant you added (that's why you should add it three times three different bottles of liquid glass over three months as I will mention below, that way, if it does blow in another area you will most likely SEAL that area also). But buy this and try it even if your vehicle fails the 45 minute test after 10 minutes. Sometimes, it will still seal the leak, or at least slow it down. Also, you can add this once a month for three months, and maybe that will work also (this gives you a month to see how the car performs under various conditions, and for the reason I just mentioned above). If you need the car to last for just a short while (month to six months) this can be a quick fix to hold you over until you can sell the car (under buyer be where conditions) or get it to the shop when you have the money. $15 and a few minutes of your time OR the mechanic, you have to decide. Good luck. I'm a retired mechanic with two degrees in Diesel mechanics and I ran a shop for a year.... :)

Product features

Permanent Coolant Leak Repair with K-Seal

Coolant leaks don’t have to result in costly repair bills – simply add K-Seal to your coolant system for a quick and permanent fix. K-Seal is trusted by millions of customers worldwide, and the only coolant leak repair fluid carried by the AA, the UK’s largest roadside repair company.

K-Seal’s unique formula will seek out holes and cracks, and permanently seal them, with no adverse impact on the efficiency of your engine cooling.

Coolant System Sealer

Once the crack or hole has been located, the microfibers instantly begin to mesh together within the gap, building a seal literally fiber by fiber to stop the coolant leaking through the gap.

The particles in our K-Seal products are very precisely designed to be large enough to repair holes up to 0.635mm in size but deliberately small enough to never block any passageways or tubes within the cooling system, including those inside the heater core and radiator.

Once the microfibers have sealed and fixed the leak, a combination of exposure to either the external atmosphere or the gases within the combustion chamber and the heat within the cooling system and engine causes the K-Seal formula to cure. This results in an extremely strong and permanent seal able to withstand even the high pressures from the combustion chamber. K-Seal Ultimate is able to repair head gasket failures, even where the cooling system is being over-pressurised by exhaust gases entering the system.

Common Coolant Leaks

K-Seal can deal with all of these leaks and more, as long as they are identified as early as possible. It is easy to use – simply shake it and pour it into the coolant mixture and it will work automatically.

BlueDevil 32oz Head Gasket Sealer w/Radiator Flush

Based on 134 reviews Check latest price

Product description

The Blue Devil Engine and Cooling Sealant has the remarkable ability to repair and seal leaks in freeze plugs, leaking radiators and heater cores, cracked or warped heads and fix most blown head gasket by forming a permanently seal. The Blue Devil Engine and Cooling Sealant will also work on internal gasket leaks, where small amounts of coolant seep into the engine oil. Contains no solid or particulate matter. It is non-clogging and will not harm your engine. Bonds to metal, aluminum, cast, alloy or plastic. Is safe and easy to use. Works on cars, trucks, vans and SUV's with gasoline or diesel engines. Independent laboratory tests and confirm Blue Devil is the only sealer known to form a permanent seal and does not rely on particles, temporarily plugging leaks.

  • Permanently Seals Blown Head Gaskets
  • Permanently Seals Leaking Radiators
  • Permanently Seals Warped & Cracked Heads
  • Permanently Seals Leaking Heater Cores
  • Includes 32oz Head Gasket sealer and 32 oz Flush

User questions & answers

Question: New radiator do i still flush
Answer: yEP, you want to flush the engine too that's why you remove the thermostat as part of the process.
Question: Can thermostat be replaced afterwards once the Blue Devel repairs have been made
Answer: Yes. The reason you remove the thermostat is to allow full flow of the coolant and blue devil liquid. After the repair is made you want to reinstall or replace the thermostat so the engine warms up and operates correctly. Also make sure that you have the heater controls in the full warm setting so that the coolant going through the heater core is not restricted while the blue devil fluid is being circulated.
Question: After sealing the leak, does blue devil need to be drained and fresh antifreeze used
Answer: Just follow the instructions on the label. I drained the radiator after treatment showed no leaks after 100 or so miles. My car still does not leak and it runs almost like new even though it has 147k on the odometer.
Question: What is the warranty or guarantee if the product doesnt work
Answer: Blue devil will not warrantee their product if bought from amazon or eBay. It Says this directly on their site. If bought from an authorized retailer and it happens to not work within 60 days of purchasing then you can get your money back.

Head Gasket Sealer for 4 Cylinder Engines - Steel Seal

Based on 118 reviews Check latest price

Product description

Steel Seal, with it's 99% success rate, will permanently seal your blown gasket or cracked head, or receive a full refund under our money back guarantee. Steel Seal head gasket sealer is an award winning formula that is triple-patented in the U.S.A. Steal Seal head gasket repair is a green transparent liquid formula that permanently seals a crack in you head gasket.

Steel Seal Head Gasket Sealer permanetly repairs blown head gasket leaks, cracked heads, heater cores and freeze plugs. Easy to use for the Do-It-Yourself repair. Single repair for all 4 cylinder engines.

  • Permanently seals head gasket leaks
  • Do-It-Yourself pour in head gasket fix
  • Award winning, triple-patented formula
  • Backed with a 100% Money-Back Guarantee
  • Used for all 4 cylinder engines

User questions & answers

Question: How I put it
Answer: Look for my past answers. I wrote down the process step by step.
Question: can you use for a 250cc air cooled motorcycle
Answer: Save your money. Buy something else.

K&W 401232 Permanent Head Gasket & Block Repair with Nanotechnology - 32 Fl Oz

K&W

Based on 178 reviews Check latest price

Product description

Using Nanotechnology, this product fills in cracks & crevices other products can't, making a stronger, more solid bond that's permanently hardened to the surface area.

  • Package length: 4.394 cm
  • Package width: 8.610 cm
  • Package height: 24.206 cm
  • Product Type: AUTO ACCESSORY

User questions & answers

Question: I have trailblazer 2005 modal 6 cylendar and before somedays my truck is overheating and water throwing out i need to ask about this product is good
Answer: I have a 1995 Mercury Grand Marquis I used this product on. The problems went away for about 3000 miles before coming back. Because otherwise my car is in good shape, I ultimately decided to get a new head gasket installed.
Question: how does this not seal the thermostat
Answer: Directions say to take thermostat out.
Question: what does it do to a good radiator . does it build up inside the tubes
Answer: I will get a thing layer, but won’t block the radiator tubes. But actually does work A+
Question: how do I add it? just pour into antifreeze
Answer: This product has to be used without antifreeze. You have to drain out your cooling system. This company does make a product that you can mix with antifreeze though.

Blue Devil (00209-6PK) Pour-N-Go Head Gasket Sealer - 16 Ounce, (Pack of 6)

Blue Devil

Based on 2 reviews Check latest price

Product description

BlueDevil Head Gasket Sealer is formulated for the Do-it-Yourself customer who has limited time, or is not mechanically inclined. The 16 Ounce is intended for the customer seeking a single repair on a 4 or 6 cylinder engine.

  • Contains No Solid Or Particulate Matter That Can Harm A Vehicles Engine
  • Permanent Repair For Head Gaskets, Heater Cores, Freeze Plugs, And Cooling System Leaks
  • Package Weight: 4.195 Kilograms
  • Package Dimensions: 15.24 L X 20.828 H X 21.59 W (Centimeters)

BlueDevil Pour-N-Go Head Gasket Sealer

BlueDevil Products

Based on 591 reviews Check latest price

Product description

BlueDevil Head Gasket Sealer is formulated for the Do-it-Yourself customer who has limited time, or is not mechanically inclined. The 16 Ounce is intended for the customer seeking a single repair on a 4 or 6 cylinder engine.

  • Do-It-Yourself Formula
  • Easy to Use Pour-n-go
  • Used for 4 cylinder and v-6 engines
  • Permanently Seals Blown, Cracked or Leaking Head Gaskets

User questions & answers

Question: where do you pour this stuff in if you have a radiator without cap
Answer: Correct answer according to directions on bottle is through the top radiator hose. DO NOT pour into the expansion reservoir.
Question: I have coolant leaking out of the engine from the heads. Will this work for external leaks
Answer: I used it on my Prius ,with 260000miles on it. Now 291000 without any problems
Question: How much do I put in my Chevy cobalt
Answer: Depends on how badly your head gasket is leaking. If it's a small leak my answer would be do not use this product EVER. If your car is absolutely trashed and this it a last ditch effort to keep it running (and if you don't mind that the product may clog your thermostat, radiator and heater core) then use the whole bottle as the directions instruct.I would HIGHLY suggest you read all one star reviews on this product before buying. One of the lowest rated products on Amazon for a reason. Ruined my engine and I had to take them to small claims court to get my damages covered.
Question: about 30 minutes into the running process the heater started blowing cold. is this normal
Answer: No it's not normal --- on my jaguar XJ8 -it did more than heater coils and totally plugger up the entire radiator -- water not flowing --- blowing a few hoses -- did something to the thermostat and with all that ( there more detailed from the Jaguar dealership cost to repair $42,000.00 ) Blue Devil's answer -----------------!-----------!-------! ---- $1500.00 and good buy ------ check the web sites you will be amazed at what you find out about these complaints --- and they don't pay for damage repair caused by their product---if I had checked first I never would have used a product from this company

K-SEAL Coolant Leak Repair, ST5501 8oz, Multi-Purpose Formula Stops Leaks in the Radiator, Head Gasket, Block, Water Pump Casing, Heater Core, and Freeze Plug - Pour and Go - Trade Trusted-Stop Leak

K-Seal

Based on 4 reviews Check latest price

Product description

K-Seal 8 fluid ounce bottle is effective to 20 quarts cooling capacity. Just shake, pour and go. It repairs leaks and cracks in radiator, head gasket, heater core, freeze plugs, water pump casing, cylinder heads and engine blocks.

  • REPAIRS IN MINUTES: Formulated to permanently weld radiators, including hard plastic aluminum heads and blocks in old and new cars. The only car radiator and gasket sealant university tested to meet ASTM D3147. Save time/money. US Bestseller
  • SEALS CRACKS AND STOPS LEAKS: A DIY alternative to costly repairs, our coolant leak fix permanently seals cracks and holes! It quickly repairs your leaking radiator, freeze plug, heater core and water pump casing with no adverse impact on efficiency.
  • POUR AND GO: Our cooling system sealer is easy to use: just shake the bottle, add to your radiator/overflow and run the engine! Unlike some traditional products, it mixes with all types of antifreeze, absolutely no draining or flushing required.
  • SCIENTIFICALLY TESTED: Safe and effective, our cracked block repair can seal leaks up to 1/32 of an inch! Once cured, the repair withstands the high pressure of the combustion chamber, all without failing or clogging the cooling system.
  • CUSTOMER SUPPORT: If K-Seal engine coolant leak stop doesn’t seal, the system might be over-pressurized. Check the Technical Specification section of this page for extra instructions for a successful repair. Over 8 million bottles sold worldwide!

User questions & answers

Question: can you mix this with barstop if you all ready put that in the radiator
Answer: I did mix this with Irontite All Weather Seal. Did the K-seal first. Irontite a week later. Just to be sure. Since they both said it can remain in the system. Two weeks, still good.
Question: Can you use this in a 2013 escape
Answer: Unless specifically told to use no heating system sealants I have no reason I can think of you can't use it. I used some but sparingly until it got the job done. Its a little bottle but still have half left. It's been okay for about 6 months now.
Question: Does it discolor the antifreeze? Thanks
Answer: Unfortunately I can't say. I have a GM vehicle that uses the orangish color engine coolant and it and this product are so close in color it's hard to say if it would discolor the usual green-colored coolant found in non-GM vehicles. The other challenge is that I can only look at the coolant through an overflow reservoir and it's so dark when I look inside (I have to use an LED flashlight to see it adequately) that it would be hard to tell if there was any discoloration.
Question: will this work for leakey gaskets
Answer: This is "liquid glass" that dries rock hard and will seal your head gasket leak (its been used in farm equipment for over 75 years and is WELL proven to work, and it was discovered over a hundred years ago), but you MUST perform a simple test. Start your vehicle, let it idle for 45 minutes straight. If the temperature gauge does not indicate that your engine is overheating, then this product will most likely work. No overheating at an idle for 45 minutes MEANS that the head gasket leak is still small enough to be filled by this liquid glass. Shake the container for 30 seconds, put the liquid in your COOLANT system, drive for an hour (or other words, operate at normal temperature, especially if its an aluminum block with cast iron heads), and then let it sit for 24-48 hours (the longest time is better). This sitting time allows the liquid glass to harden completely through. If it overheats then, it most likely its a thermostat or water pump or lower radiator hose sucking shut under load (sometimes the upper one also) or radiator or radiator fan or leaking core plug or leaking coolant storage unit OR your ENGINE OIL is very low from leaking (completely different problem that has nothing to do with the coolant system, but much to do with the cooling of the engine also) or heat indicator gauge or it still could be a blown head gasket, because the hole is just too big for the sealant to seal it up OR the head gasket BLOWS in another area after you have sealed up the first hole with the coolant sealant you added (that's why you should add it three times three different bottles of liquid glass over three months as I will mention below, that way, if it does blow in another area you will most likely SEAL that area also). But buy this and try it even if your vehicle fails the 45 minute test after 10 minutes. Sometimes, it will still seal the leak, or at least slow it down. Also, you can add this once a month for three months, and maybe that will work also (this gives you a month to see how the car performs under various conditions, and for the reason I just mentioned above). If you need the car to last for just a short while (month to six months) this can be a quick fix to hold you over until you can sell the car (under buyer be where conditions) or get it to the shop when you have the money. $15 and a few minutes of your time OR the mechanic, you have to decide. Good luck. I'm a retired mechanic with two degrees in Diesel mechanics and I ran a shop for a year.... :)

Product features

Permanent Coolant Leak Repair with K-Seal

Coolant leaks don’t have to result in costly repair bills – simply add K-Seal to your coolant system for a quick and permanent fix. K-Seal is trusted by millions of customers worldwide, and the only coolant leak repair fluid carried by the AA, the UK’s largest roadside repair company.

K-Seal couldn’t be simpler to use. K-Seal’s unique formula will seek out holes and cracks, and permanently seal them, with no adverse impact on the efficiency of your engine cooling.

Coolant System Sealer

Once the crack or hole has been located, the microfibers instantly begin to mesh together within the gap, building a seal literally fiber by fiber to stop the coolant leaking through the gap.

The particles in our K-Seal products are very precisely designed to be large enough to repair holes up to 0.635mm in size but deliberately small enough to never block any passageways or tubes within the cooling system, including those inside the heater core and radiator.

Once the microfibers have sealed and fixed the leak, a combination of exposure to either the external atmosphere or the gases within the combustion chamber and the heat within the cooling system and engine causes the K-Seal formula to cure. This results in an extremely strong and permanent seal able to withstand even the high pressures from the combustion chamber. This is how K-Seal Ultimate is able to repair head gasket failures, even where the cooling system is being over-pressurized exhaust gases entering the system

Common Coolant Leaks

K-Seal can deal with all of these leaks and more, as long as they are identified as early as possible. It is easy to use – simply shake it and pour it into the coolant mixture and it will work automatically.

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