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K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz
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K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz
Rated No.1 Permanent molecular seal that’s as strong as steel.
K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz
CRC

Item #: 221124681

K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz

85% of respondents would recommend this to a friend

Item #: 221124681

XPF 3437

Price Details

Excluding Shipping & Custom charges ( Shipping and custom charges will be calculated on checkout )

*All items will import from US

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Order now and get it around Tuesday, October 06
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Rated No.1 Permanent molecular seal that’s as strong as steel.
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What Stands Out

Permanent Seal
K&W 401016 provides a long-lasting solution for leaks in engine blocks and radiators, ensuring durability and reliability over time, unlike temporary fixes offered by competitors.
Metallic Formula
The advanced metallic formulation creates a robust barrier against leaks, enhancing the product's ability to withstand high temperatures and pressure, making it suitable for various vehicle types.
Easy Application
Designed for user-friendly application, this 16 oz product simplifies the sealing process, saving time and effort for vehicle owners, who can achieve professional results without needing mechanical expertise.

Product Details

Seals Cracks & Holes in Engine Blocks, Radiators & Heater Cores. Tested by an Independent Lab. No.1 Rated Product. Shop Now on Ubuy Wallis and Futuna Islands!
Package Weight2 Pound (910 grams)

Who Should Buy?

Suitable For
  • Leaky Radiators

    Ideal for users with minor radiator leaks looking for an effective and simple fix to prevent fluid loss.

  • Older Vehicles

    Perfect for owners of older cars experiencing persistent small leaks that could lead to larger issues over time.

  • DIY Mechanics

    Great for do-it-yourself enthusiasts wanting a straightforward, non-intrusive solution to coolant leaks without major repairs.

Not Suitable For
  • Severe Damage

    Not suitable for vehicles with significant engine or radiator damage requiring professional or extensive repairs.

Product Description

K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz

Have any Query? Chat with us

Customer Questions & Answers

  • Question: What is the K&W 401016 Block Seal used for?

    Answer: The K&W 401016 Block Seal is designed to seal leaks in engine blocks and radiators. It works by creating a permanent bond with the metal surfaces, effectively preventing fluid loss and enhancing engine performance. This can be particularly useful for older vehicles or those with minor leaks, ensuring that you don't experience overheating or coolant loss during operation.
  • Question: Is K&W 401016 safe for all types of engines?

    Answer: Yes, K&W 401016 Block Seal is formulated to be safe for use in all types of gasoline and diesel engines. It contains metallic particles that act as fillers to seal leaks without causing damage to engine components. It is ideal for both classic cars and modern vehicles, making it a versatile choice for various applications.
  • Question: How do I use the K&W 401016 Block Seal?

    Answer: To use K&W 401016 Block Seal, first ensure the engine is cool and find the source of the leak. Pour the entire contents of the 16 oz bottle into the radiator or overflow tank. Then, run your engine to help circulate the product throughout the cooling system. It is crucial to follow the manufacturer's instructions on dosage and run time for optimal results.
  • Question: How long does K&W 401016 last after application?

    Answer: Once applied, K&W 401016 Block Seal can provide a long-lasting seal. Its advanced formula is designed to bond permanently with metal components, effectively preventing leaks for the life of the engine. However, results can vary based on the severity of the leak and the condition of the engine.
  • Question: Can K&W 401016 Block Seal fix a blown head gasket?

    Answer: K&W 401016 Block Seal is not explicitly designed to fix a blown head gasket. It may temporarily reduce symptoms related to coolant leaks, but for severe issues like a blown head gasket, a proper mechanical fix is generally required. Use this product primarily for minor leaks to prolong engine life and avoid overheating.
  • Question: Is K&W 401016 compatible with antifreeze?

    Answer: Yes, K&W 401016 Block Seal can be used in systems that contain antifreeze. It is compatible with most cooling system fluids, allowing you to treat leaking radiators and blocks without needing to drain the system completely. This feature makes it a convenient option for quick repairs without disrupting ongoing maintenance.
  • Question: What are the advantages of using K&W 401016 Block Seal?

    Answer: The primary advantages of K&W 401016 Block Seal include its permanent sealing capabilities, compatibility with various engine types, and ease of application. It eliminates the need for costly repairs by offering a simple, effective solution for leaks, thus improving engine reliability and performance.
  • Question: Can I use K&W 401016 on a motorcycle?

    Answer: Yes, K&W 401016 Block Seal is suitable for use in motorcycles as well as cars and trucks. Its formulation works effectively to seal leaks in smaller engines, helping to maintain proper coolant levels and prevent overheating, which is essential for motorcycle performance.
  • Question: What should I do if the leak persists after using K&W 401016?

    Answer: If the leak continues after using K&W 401016 Block Seal, it may indicate a more severe issue that requires professional inspection. It's advisable to consult a mechanic for a comprehensive diagnosis to determine whether a more permanent mechanical solution is needed.
  • Question: Where can I buy K&W 401016 Block Seal Permanent Metallic Block & Radiator Seal - 16 Oz?

    Answer: You can buy K&W 401016 Block Seal Permanent Metallic Block & Radiator Seal - 16 Oz at Ubuy, which offers a wide range of automotive products. Ubuy provides convenient access and various purchasing options for customers in Wallis and Futuna Islands, making it easier to find this effective leak sealant.

CRC Radiator Editorial Review

K&W 401016 Block Seal Permanent MetallicTM Block & Radiator Seal - 16 Oz is designed to effectively seal block leaks, making it ideal for addressing head gasket issues. Users have noted the importance of following precise directions, such as using water instead of anti-freeze and allowing the engine to run at operating temperature for optimal results. Many reviewers have shared their positive experiences, emphasizing how the product has helped slow down leaks, although complete fixes may vary depending on the severity of the damage. Overall, this product is seen as a reliable solution for specific coolant system problems when used correctly.

Customer Reviews & Ratings

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Pros

  • Effectively reduces leaks in radiator systems
  • Users recommend following instructions carefully
  • Important to flush system before application
  • Can stop leaks after driving some distance
  • Works better when engine is at operating temperature

Cons

  • May not completely fix severe leaks

Platform Trust & Buyer Confidence

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4.2/5 9477 reviews
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JK
Jasmin
Verified buyer

“Great products and very good service: very easy and very fast international delivery.”

9 September 2026 · via Trustpilot
AG
Anke
Verified buyer

“Wonderful online shopping experience, smooth transaction from the start. Payment method works conveniently and delivery is unexpectedly fast and reliable. You go the extra mile for service. What makes this even more amazing, you deliver to Namibia. I will remain a happy Ubuy customer and will increase my purchases for sure! Thank you!”

10 September 2026 · via Trustpilot
H
Hazel
Verified buyer

“Very easy to find the products what you need, and so fast delivery, that’s why I highly recommended to others costumers to used ubuy.”

10 September 2026 · via Trustpilot
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Opaleye
Verified buyer

“I received exactly what I ordered I was skeptical about your site because that was my first time to order. But the order came timely and neatly packaged. I was not disappointed. Thank you.”

11 September 2026 · via Trustpilot
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Adele
Verified buyer

“Easy to find and order what you want on the website. Delivery is quick to the UK”

8 September 2026 · via Trustpilot
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Important information

  • Limitations : For products shipped internationally, please note that any manufacturer warranty may not be valid; manufacturer service options may not be available; product manuals, instructions, and safety warnings may not be in destination country languages; the products (and accompanying materials) may not be designed in accordance with destination country standards, specifications, and labeling requirements; and the products may not conform to destination country voltage and other electrical standards (requiring use of an adapter or converter if appropriate). The recipient is responsible for assuring that the product can be lawfully imported to the destination country. When ordering from Ubuy or its affiliates, the recipient is the importer of record and must comply with all laws and regulations of the destination country.
  • Not all the products listed on Ubuy are for sale, as Ubuy is a global search engine. Products are subject to export/trade regulations.

XPF 3437

Order now and get it around Tuesday, October 06

QTY:

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Features & Benefits

  • Forms a permanent bond stronger than steel.
  • Seals cracks in engine blocks, gaskets, and radiators.
  • Tested by independent labs for reliability.
  • Suitable for all diesel and gasoline vehicles.
  • Withstands extreme pressure and temperature.
  • Professional grade formula exceeds ASTM D6107.

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