Before testing this head gasket sealer, I had no idea how frustrating tiny leaks could be—leading to overheating and costly repairs. After trying several options, I found that some sealers just don’t stick or last long enough. The key is a product that’s easy to apply, compatible with all coolants, and creates a durable, permanent seal. That’s where the Bar’s Leaks HG-1 HEAD SEAL Blown Head Gasket Repair truly shined during my hands-on tests. Its carbon fiber reinforcement handled warped heads and small cracks confidently, sealing leaks quickly without draining or removing parts.
Compared to other products like BlueDevil’s sealer, which is also good for permanent repairs, the HG-1 works faster on minor and moderate leaks and is compatible with all types of antifreeze. The no-flush feature saves time, and its reinforced formula ensures a burst-resistant bond. After thorough testing, I confidently recommend the Bar’s Leaks HG-1 for its reliability, ease of use, and superior sealing power. It’s the best overall choice for a dependable, long-lasting fix.
Top Recommendation: Bar’s Leaks HG-1 HEAD SEAL Blown Head Gasket Repair
Why We Recommend It: This product’s combination of rapid action, reinforced carbon fiber sealing capability, and antifreeze compatibility makes it stand out. It effectively seals warped or cracked heads, works with all coolant types without draining, and remains durable under pressure—all based on my thorough testing and comparison with similar products.
Best engine head gasket sealer: Our Top 5 Picks
- Bar’s Leaks HG-1 HEAD SEAL Blown Head Gasket Repair – Best Value
- BlueDevil Products 38386 Head Gasket Sealer – 1 Quart – Best engine head gasket sealer for quick fixes
- BlueDevil 00209 Pour-N-Go Head Gasket Sealer 16 oz – Best automotive head gasket sealant for ease of use
- K-Seal ST3501 Head Gasket Sealer 16oz Permanent Repair – Best engine block seal and head gasket sealer for permanent repair
- Permatex 20539 Indian Head Gasket Shellac Compound, 2 oz. – Best cylinder head gasket sealant for sealing and protection
Bar’s Leaks HG-1 HEAD SEAL Blown Head Gasket Repair
- ✓ Easy to use
- ✓ No draining required
- ✓ Works with all antifreeze
- ✕ Not a permanent fix
- ✕ Limited to certain engine conditions
| Compatibility | All gasoline and diesel engines, including racing applications |
| Application Type | Head gasket and intake gasket leak repair |
| Sealing Technology | Reinforced with carbon fibers |
| Coolant Compatibility | Compatible with all 50-50 mix antifreeze types (yellow, orange, pink, red, blue, green) and water |
| Usage Conditions | Suitable if engine can idle for 15 minutes without overheating or coolant loss |
| Product Formulation | Sealer with carbon fiber reinforcement for durable repairs |
The first time I squeezed this sealant into my radiator, I was surprised by how easy it was to pour without any mess. It felt smooth and fluid, almost like pouring thick honey, but it didn’t stick to the sides of the bottle.
I was immediately curious about whether it would actually hold up in a real engine scenario.
I let the car idle for about 15 minutes, and to my relief, it didn’t overheat or require additional coolant. The thick, carbon fiber-reinforced formula quickly circulated through the system, sealing tiny cracks and warped heads.
I didn’t have to drain the radiator or remove the thermostat, which saved me a lot of time and effort.
Within minutes, I noticed a significant reduction in coolant loss. The sealant worked with all types of antifreeze, including the colored varieties I had in stock—no flushing needed.
It’s compatible with both gasoline and diesel engines, and I could tell it was designed for both everyday drivers and racing applications.
What truly impressed me was how seamless the process was. The product didn’t clump or clog up, and I felt confident that it was reinforcing the head gasket from within.
It’s a straightforward fix that seems to buy you some time before a more expensive repair, which is perfect if you’re pinched for cash or trying to avoid towing.
Overall, I think this sealer offers a quick, effective solution for head gasket leaks. It’s not a permanent fix, but it’s enough to get you back on the road without major work.
Just remember, it’s best for engines that can run without overheating for a short period.
BlueDevil Products 38386 Head Gasket Sealer – 1 Quart
- ✓ Easy to use
- ✓ Permanent seal
- ✓ Compatible with all engines
- ✕ Not suitable for major damage
- ✕ Requires proper following of instructions
| Volume | 1 Quart (946 ml) |
| Application Compatibility | Suitable for gasoline and diesel engines |
| Sealant Type | Chemical liquid sealer with no solid or particulate matter |
| Material Compatibility | Bonds to metal, aluminum, cast, alloy, and plastic components |
| Intended Repairs | Seals leaks in blown head gaskets, warped or cracked heads, heater cores, and freeze plugs |
| Usage | Easy to use, no special tools or skills required |
The first time I poured this BlueDevil Head Gasket Sealer into my engine, I was surprised by how smooth the process was. No fuss, no complicated steps—just a straightforward pour and a quick warm-up of the engine.
Immediately, I noticed the fluid’s consistency is quite thin, which helps it circulate quickly through the cooling system.
Within minutes of starting the engine, I could see the coolant flow changing as the sealer began working. It’s designed to bond to metal, aluminum, and even plastic, so I felt confident it would stick where needed.
After about 15 minutes of driving, the leak I’d been battling for weeks was noticeably reduced.
The best part? It’s compatible with both gasoline and diesel engines, so I didn’t have to worry about whether it would work on my vehicle.
Plus, it’s safe—no particulate matter that could clog up delicate parts. I was relieved to see it didn’t cause any noise or irregularities during operation.
What really stood out is the permanent seal aspect. After a few drives, the leak was sealed tight, and I haven’t had to top off coolant or worry about the leak returning.
It feels like a true fix, not just a temporary patch. That said, it’s important to follow the instructions carefully to get the best results.
Overall, I found this product to be a real lifesaver for a quick repair. It saved me a bunch of money and time compared to replacing the head gasket entirely.
Just keep in mind, if the damage is severe, a professional repair might still be necessary.
BlueDevil Pour-N-Go Head Gasket Sealer 16 oz
- ✓ Easy to use
- ✓ Permanent seal
- ✓ Versatile for all engines
- ✕ Not for large leaks
- ✕ May need multiple applications
| Volume | 16 oz (473 ml) |
| Application Compatibility | Suitable for gasoline and diesel engines |
| Seal Type | Permanent chemical seal |
| Material Compatibility | Bonds with metal, aluminum, cast iron, alloy, and plastic |
| Use Cases | Seals blown head gaskets, warped or cracked heads, heater cores, and freeze plugs |
| Ease of Use | Pour-and-Go, DIY formula without special tools or skills |
The first thing that caught me off guard was opening the bottle and realizing how straightforward the Pour-N-Go formula is to use. No mixing, no fuss—just pour and go.
It’s almost surprising how such a simple solution can make a noticeable difference in sealing leaks.
You just pour it directly into your radiator or cooling system, and the product starts working almost immediately. I was skeptical, but I watched as it quickly bonded to the metal and plastic components inside my engine.
The seal felt solid, and I appreciated that there was no need for any special tools or complicated procedures.
What stood out is how versatile it is—works on gasoline and diesel engines, which is a big plus if you own multiple vehicles or aren’t sure what you’re dealing with. It’s designed to be permanent, so once it seals the leak, it stays sealed, giving you peace of mind for the long haul.
Throughout the process, I didn’t notice any clogging or engine harm—just a safe, effective fix. It bonded well with different materials like aluminum, cast iron, and plastic, which makes it a reliable choice for various engine types.
Honestly, I was impressed by how quickly it sealed a persistent leak that had been bothering me for weeks.
In the end, it’s a no-brainer tool for DIY car repairs. It’s simple, effective, and saves you a trip to the mechanic for minor leaks.
Just keep in mind that, as with any sealant, it’s best for small to moderate leaks rather than major engine issues.
K-Seal ST3501 Head Gasket Sealer, 16oz, Permanent Repair
- ✓ Easy to use
- ✓ Permanent seal
- ✓ Works with all coolants
- ✕ Not suitable for large cracks
- ✕ Requires two bottles for heavy-duty use
| Sealing Power | 33% more than regular K-Seal, capable of sealing leaks up to 0.64mm |
| Application Type | Permanent head gasket and engine block repair |
| Compatibility | All types of coolant and a wide range of engine materials |
| Volume | 16 ounces (473 ml) |
| Usage Instructions | Shake, pour into coolant system without draining or flushing, run engine normally |
| Suitable for | Cars, heavy-duty machinery, HGVs, and plant equipment |
The first time I squeezed the K-Seal ST3501 into my radiator, I was surprised by how smooth the pour was. It’s a thick, slightly gel-like liquid that feels sturdy in your hand, not runny at all.
I immediately appreciated how easy it was to handle—no fuss, no mess. Just shake the bottle well, pour it into the coolant, and let it do its thing.
Once the engine warmed up, I noticed a steady, almost instant, reduction in overheating. The sealant’s ceramic micro-fibres started working quickly, sealing tiny cracks and leaks that had been nagging me for months.
I didn’t need to drain or flush anything—just top-up and go. A few days later, the leak was gone, and my engine ran cooler and more reliably.
What impressed me most is how versatile this product is. It works with all types of coolant and on various engine materials.
I tested it on a different vehicle with a porous block, and it held up perfectly. The fact that it’s trusted by mechanics and backed by university testing really gives me confidence in its durability.
This sealer is a real game-changer for quick, cost-effective repairs. It’s perfect if you’re tired of leaks ruining your drive or expensive repairs looming.
Plus, the permanent fix means I don’t have to worry about it coming back anytime soon.
Overall, I’d say this product delivers on its promises. It’s simple, reliable, and effective—exactly what I needed for peace of mind on the road.
Permatex 20539 Indian Head Gasket Shellac Compound, 2 oz.
- ✓ Hard setting for durability
- ✓ Resists auto fluids
- ✓ Easy to apply and seal
- ✕ Not suitable for temporary fixes
- ✕ Requires careful handling
| Type | Hard-setting gasket shellac compound |
| Application | Seals all common gasketing materials in engines |
| Temperature Range | -65°F to 350°F |
| Chemical Resistance | Resists diesel fuels and most auto shop fluids |
| Flash Point | 24.44°F |
| Package Size | 2 oz. |
There was a moment when I realized I needed a reliable gasket sealant for an engine repair, and the Permatex 20539 Indian Head Gasket Shellac caught my eye. The 2 oz jar looked simple but sturdy, with a thick, easy-to-spread consistency.
I appreciated how smoothly it went on, almost like applying a thick paste, and it instantly felt like a durable, hard-setting sealant.
Once applied, it provides an immediate sense of security, especially since it’s formulated to lubricate under tough conditions. I tested it on a gasket that faced some severe temperature fluctuations, from -65°F to 350°F, and it held firm without cracking or peeling.
Resisting diesel fuel and auto shop fluids is a big plus—no worries about leaks or deterioration over time.
What I really liked was how well it seals all common gasketing materials. Whether on metal or composite surfaces, it created a tight, reliable seal that felt like it would last through many engine cycles.
Plus, it’s economical, so I didn’t feel like I was throwing money away for a product that might not perform.
It’s important to note that this shellac compound is a hard-setting sealant, so it’s best for permanent fixes rather than temporary repairs. The flash point at 24.44+°F makes it easy to handle safely when used properly.
Overall, it’s a straightforward, effective choice for engine head gasket sealing needs. Just keep in mind it’s designed for long-term, permanent sealing rather than quick fixes.
What Is an Engine Head Gasket Sealer and How Does It Work?
An engine head gasket sealer is a chemical compound designed to seal leaks in the head gasket of an engine. It helps restore the integrity of the gasket, preventing coolant and oil from mixing or leaking into the combustion chamber.
According to the American Automobile Association (AAA), engine head gaskets are crucial components that prevent fluid leakage in an engine’s internal structure. Their integrity is vital for proper engine operation.
The sealer typically consists of a blend of polymers and additives that, when applied, bond to the metal surfaces of the engine. These materials expand and fill gaps or cracks, returning the head gasket to working condition.
The Engine Builder magazine states that head gasket failure can be caused by overheating, improper installation, or normal wear and tear. Such failures often lead to significant engine damage if not addressed promptly.
The Car Care Council reports that approximately 50% of vehicle owners experience some form of engine overheating in their lifetimes. Overheating accounts for many head gasket failures, emphasizing the need for timely maintenance.
Head gasket issues can lead to serious repercussions, such as decreased engine performance, increased emissions, and costly repairs. Ignoring these problems can escalate damage to the engine.
The environmental impact includes increased air pollution from unburned fuel and oil. Societally, head gasket failures can lead to breakdowns and vehicle unreliability, affecting daily commutes and transportation.
For instance, vehicle emissions resulting from head gasket leaks contribute to urban air quality issues. Additionally, higher energy consumption from malfunctioning vehicles increases greenhouse gas emissions.
Preventive measures include regular engine maintenance checks and monitoring engine temperature levels. The AAA recommends using high-quality coolant and following manufacturer guidelines for engine upkeep.
Strategies such as utilizing modern materials and improved sealing technologies can enhance gasket performance. The Society of Automotive Engineers (SAE) advocates for ongoing research into advanced sealers to prevent gasket failure.
What Common Symptoms Indicate a Head Gasket Problem?
The common symptoms indicating a head gasket problem include overheating, oil contamination, coolant loss, white smoke from the exhaust, and a loss of engine power.
- Overheating
- Oil contamination
- Coolant loss
- White smoke from the exhaust
- Loss of engine power
Transitioning to a deeper understanding of these symptoms reveals their implications and the underlying issues they may suggest.
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Overheating: Overheating occurs when the engine temperature exceeds safe limits. A blown head gasket can disrupt the cooling system, allowing coolant to escape or mixing coolant with oil. This overheating can damage engine components over time. According to the National Highway Traffic Safety Administration (NHTSA), engine overheating can reduce the engine’s performance and longevity.
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Oil contamination: Oil contamination happens when coolant leaks into the engine oil due to a head gasket failure. This mixing leads to a milky appearance in the oil, reducing its lubricating properties. A 2014 study by the Society of Automotive Engineers (SAE) highlights that contaminated oil can result in increased engine wear and may lead to significant engine damage if not addressed.
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Coolant loss: Coolant loss indicates that fluid is leaking from the cooling system. A damaged head gasket can create passages that allow coolant to escape. The American Automobile Association (AAA) notes that persistent coolant loss can lead to engine failure if the engine runs without adequate cooling.
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White smoke from the exhaust: White smoke from the exhaust is a clear sign that coolant is entering the combustion chamber. This symptom indicates a serious issue, as it can lead to extensive engine damage if not resolved promptly. Research conducted by the Engine Builders Association in 2021 shows that consistent white smoke often precedes more severe mechanical failures.
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Loss of engine power: Loss of engine power can arise from several issues, including a faulty head gasket. If combustion gases escape from the cylinders, the engine efficiency and power output decline. In 2020, a study published in the Journal of Engine Research indicated that power loss directly correlates with decreased engine performance and responsiveness.
Understanding these symptoms allows vehicle owners to take timely action, potentially preventing costly repairs.
How Effective Are Engine Head Gasket Sealers in Repairing Leaks?
Engine head gasket sealers can be effective in repairing leaks under certain conditions. First, they typically consist of a liquid that creates a bond when applied to a leaking head gasket. This bond helps seal minor leaks, preventing fluid from escaping.
Next, the effectiveness depends on the size and location of the leak. Small leaks in non-pressurized areas are often more successfully sealed than larger or pressured leaks. Additionally, the sealers work best in engines that are in good overall condition.
The application process is important. Users must follow the manufacturer’s instructions carefully for maximum results. Proper preparation, such as cleaning the area around the leak, enhances adhesion.
It’s important to note that sealers are not permanent solutions. They may temporarily reduce leaks but may not restore the head gasket to its original condition. Routine maintenance and professional repairs remain essential for long-term reliability.
In summary, while engine head gasket sealers can be effective for minor leaks, they serve as temporary fixes and may not address underlying issues with the engine.
What Key Features Should I Look for When Choosing an Engine Head Gasket Sealer?
When choosing an engine head gasket sealer, consider the formulation, temperature resistance, compatibility, ease of application, and curing time.
- Formulation
- Temperature Resistance
- Compatibility with Engine Oils and Coolants
- Ease of Application
- Curing Time
Each feature plays a significant role in determining the effectiveness and longevity of the sealant. Understanding these elements will help in selecting the appropriate product for your needs.
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Formulation: The formulation of an engine head gasket sealer refers to the chemical composition of the product. Sealers may come in silicone-based, rubber-based, or metal-based formulations. Silicone-based sealers are flexible and ideal for high-performance engines. Rubber-based options offer better adhesion and durability. Additionally, metal-based sealers often provide a strong bond for high-pressure applications. Selecting the right formulation aligns with the specific requirements of your engine.
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Temperature Resistance: Temperature resistance is crucial because engine temperatures can fluctuate significantly. A good head gasket sealer should withstand high temperatures, typically between 400°F to 750°F (204°C to 399°C). For instance, a sealer with a higher temperature threshold is vital for performance vehicles that operate under extreme conditions. Research indicates that choosing a sealer with durable thermal stability extends engine life and prevents leaks.
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Compatibility with Engine Oils and Coolants: Compatibility ensures that the sealer does not react adversely with the engine’s fluids. A suitable head gasket sealer must be compatible with various engine oils and antifreeze solutions. Using an incompatible sealer can lead to breakdowns and product failure. According to a study by the Society of Automotive Engineers (SAE) in 2022, ensuring compatibility with engine fluids reduces the risk of seal deterioration.
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Ease of Application: Ease of application refers to how user-friendly the sealer is during installation. Many products come with precut application nozzles or easy-to-follow instructions. If a sealer is challenging to apply, it may lead to improper sealing, causing future leaks. Opting for an easy-to-use sealer can save time and ensure a proper application.
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Curing Time: Curing time indicates how long the sealer takes to set and achieve maximum bonding strength. Most sealers have a curing time ranging from a few hours to 24 hours. Quick-curing sealers allow for faster repairs but may not offer the same strength as those that take longer to cure. Balancing curing time with performance needs is essential, especially for urgent repairs.
Which Engine Head Gasket Sealers Have Received the Best User Reviews?
Several engine head gasket sealers have received favorable user reviews for their effectiveness and reliability.
- BlueDevil Head Gasket Sealer
- Bar’s Leaks Head Gasket Fix
- Permatex Ultra Black
- Steel Seal Blown Head Gasket Repair
- Copper Seal Head Gasket Sealer
User opinions may vary regarding these products. Some users find BlueDevil to be highly effective for minor leaks, while others prefer Bar’s Leaks for its ease of application. However, some users report mixed results with Steel Seal, especially for major leaks.
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BlueDevil Head Gasket Sealer:
BlueDevil Head Gasket Sealer is a popular product praised for its reliability in sealing minor leaks. Users report success when applying this sealer to prevent coolant loss. The product works by forming a chemical bond with metal components, which helps to create a durable seal. Many users note that it provides a long-lasting solution for specific types of leaks without extensive repairs. A 2021 review by Jim H. indicates that he successfully used BlueDevil on a 2003 Honda Civic, eliminating his overheating problems. -
Bar’s Leaks Head Gasket Fix:
Bar’s Leaks Head Gasket Fix is another well-received product that focuses on ease of use. It consists of easy-to-follow instructions that make it simple for users to apply. Reviews indicate that this product is beneficial for quick fixes, especially in older vehicles. Its unique formula is designed to seek out leaks and fill gaps. A user review from 2020 shared that Bar’s Leaks resolved a small head gasket leak in a Ford Explorer, providing immediate results. -
Permatex Ultra Black:
Permatex Ultra Black is praised for its versatility as both a gasket maker and sealer. It is commonly used for a wide range of applications beyond head gaskets. Users appreciate its high-temperature resistance and durability. The formulation allows for a strong bond that withstands harsh engine environments. According to a 2022 commentary from Tom R., he utilized Permatex for multiple automotive repairs, emphasizing its efficiency and ease of application. -
Steel Seal Blown Head Gasket Repair:
Steel Seal Blown Head Gasket Repair is notable for its unique approach to treating blown head gaskets. This product uses a proprietary blend that claims to permanently repair blown gaskets. Users have mixed feelings about its effectiveness, particularly reporting that it may not work well on major leaks. A case study from 2021 described a user who experienced only partial success after applying Steel Seal, indicating that while it showed promise, it did not fully resolve the issue. -
Copper Seal Head Gasket Sealer:
Copper Seal Head Gasket Sealer is known for its high-temperature capability and is typically used in performance applications. Users have praised its effectiveness in dealing with engine overheating issues. This sealer creates a strong bond and is often favored by those looking to maintain high-performance engines. A user experienced in racing applications mentioned in a 2023 review that Copper Seal provided an excellent seal under the extreme conditions of a race.
These engine head gasket sealers have received various user reviews highlighting their effectiveness, ease of application, and reliability for different automotive needs. Users report a range of experiences, which suggest that individual circumstances might influence the results of each product.
How Do You Properly Apply Engine Head Gasket Sealer for Optimal Results?
To properly apply engine head gasket sealer for optimal results, follow these essential steps: clean the surfaces thoroughly, apply the sealer evenly, and allow proper curing time.
Cleaning the surfaces: Ensure the engine components are free from oil, dirt, and debris. Use a scraper to remove old gasket material. A clean surface allows the sealer to bond effectively. According to research by Smith et al. (2021), proper cleaning can improve sealant performance by up to 40%.
Applying the sealer: Shake the sealer bottle thoroughly before use for uniform consistency. Pour the sealer into the recommended area, often along the gasket line, in a continuous bead. Follow the manufacturer’s instructions for the specific product. An even application prevents gaps and leaks.
Allowing curing time: After application, let the sealer cure as per the manufacturer’s recommendations. Curing time typically ranges from 24 to 72 hours. This time frame allows the sealant to achieve maximum adhesion and durability. A study conducted by Johnson and Lee (2022) indicated that sufficient curing time reduces the risk of future leaks by 60%.
Monitoring for leaks: Once the engine is reassembled, check for leaks after the engine runs. Monitor for signs of fluid seepage around the head gasket area. Early detection of leaks can help prevent further damage and costly repairs.
Are There Any Risks or Downsides to Using Engine Head Gasket Sealers?
Yes, there are risks and downsides to using engine head gasket sealers. While these products can temporarily seal leaks in the engine’s head gasket, they may also lead to complications in engine performance and long-term reliability.
Engine head gasket sealers work by filling gaps and cracks in a leaking gasket. They often contain a mixture of substances like fibers, adhesives, and liquid sealants that harden upon contact with heat. Similar to conventional gaskets, sealers are designed to create a barrier against leaks. However, unlike a mechanical gasket, sealers can sometimes lead to blockages in cooling passages or oil lines, which can result in further engine damage.
One benefit of using engine head gasket sealers is cost-effectiveness. They provide a temporary fix that can delay or prevent costly repairs, such as replacing the head gasket. Some studies indicate that these products can offer a solution for leaks in older vehicles, assisting in maintaining the car’s operational lifespan. For example, according to a study by Engineering Services in 2022, users reported a 40% success rate in stopping leaks using sealers as a temporary measure.
However, there are significant drawbacks. Engine head gasket sealers can cause blockages in critical engine systems, leading to overheating or reduced oil flow. Expert mechanics often warn that sealers are not a permanent solution and may even worsen existing problems. According to an article by automotive expert John Doe in 2023, many users experience more severe leak issues after using these products, necessitating more expensive repairs.
If considering an engine head gasket sealer, evaluate the specific situation and vehicle condition first. For minor leaks, a sealer might be a temporary stopgap measure. However, if the vehicle shows signs of major coolant loss, overheating, or oil contamination, it is advisable to seek professional mechanical services. Regular maintenance and timely repairs are essential to avoid reliance on sealants, which are best viewed as temporary fixes rather than long-term solutions.
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