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CRC K&W 401016 Block Seal Permanent Metallic™ Block & Radiator Seal – 16 Oz

$16.10

327 ratingsSource: Amazon

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  • Permanent molecular seal that’s as strong as steel
  • Seals cracks & holes in cast iron and aluminum engine blocks, head gaskets, freeze plugs, and copper, aluminum and bi-material radiators & heater cores
  • For use in all water-cooled diesel and gasoline vehicles
  • Withstands extreme pressure and temperatures of a cooling system and will not wash away
  • Professional grade formula exceeds ASTM D6107 for effectively sealing leaks in cooling systems

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SKU: D-B000CIPV5E Category:

Description

Forms a permanent molecular bond that’s as strong as steel. Seals cracks & holes in cast iron & aluminum engine blocks, head gaskets, freeze plugs, & copper, aluminum & bi-material radiators & heater cores. Tested by an Independent test lab. Rated No.1

Imported customer feedback

What customers reported

3.8 / 5 327 ratings

Source: Amazon. These reviews were imported from the source marketplace and are not reviews of purchases made on this website.

13 reviews for CRC K&W 401016 Block Seal Permanent Metallic™ Block & Radiator Seal – 16 Oz

  1. TxT

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    These do work! With certain assumption, depends on the leak or crack in your head gasket. I followed the directions from TrustMyMechanic . com in the you tube channel. […] . His directions made more sense to me. You really have to drain your existing coolant out, flush it a couple of times, then fill it with tap water and then poor this bottle into the radiator cap opening. Then just drive your car for at least 500 miles. It took me about a week of driving to work and back to hit 500 miles. I check my radiator every day to top it off with water before going to work and noticed it stop leaking after about 75 miles on the odometer. So what does that mean…you really have to drive it around, get the engine hot enough and let the water/block seal get into the seams of the crack/leak. The directions on the bottle may work, but I think by doing it this way, I think it works a lot better. Like I said, it stopped leaking at around 75 miles into the 500 miles. I guess if you drive it over 500 miles and it is still leaking, then I think the crack/leak is way to big for this product to work. Or it could be leaking outside of the cylinder head. So after the 500 miles, verify that it stopped leaking by openning up your radiator cap and looking into your radiator. The top of the radiator should still be wet, there should still be water floating around at the top. If you can see the radiator fins and it’s bone dry, then you still have a leak. If you are good, drain the tap water/block sealer, then flush it a couple of times. Then fill it up with coolant for your car.I use this product on a 2005 Toyota Tacoma Pre-Runner. Symptom of a crack/leak in your head gasket: Got a P0300 (random misfire), P0304 (cylinder 4 misfire), P0306 (cylinder 6 misfire). For this truck, when you drive it around town, you can hear water swooshing back and forth inside the engine bay. This is because when there is a leak in the gasket, the pressure and gases from the cylinder head pushes back into the coolant chambers and creates bubbles/air pockets thus there is open space in your coolant block that allows the coolant to move around. So if you hear that, it’s an indication that you got coolant issues. Also, you will be losing coolant everyday or two when you check your radiator.Hope that helps…

  2. Richard Phillip Pomeroy

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    So far so good. I used this sealer close to Trust My Mechanic instructions (you tube). I did drain and flush cooling system several times before use of sealer. All antifreeze flushed out of system. I drained system by removing hose at bottom of radiator. Also I removed threaded drain plug on block each time I flushed. I added sealer after mix with water in 1 gallon jug. Half was put in to radiator the rest was put into thermostat opening. Thermostat was replaced and used during the 500 mile run in. Radiator was filled to the top before car started. Heater was turned on wide open for first 50 miles. I only have 250 miles on car so far but the internal leak has stopped. I have not added any water to cooling system after the addition of sealer. Water lever is good in overflow tank. Car is not over heating. The plan is to put 500 miles total on the car then drain cooling system and put in antifreeze 50/50. I hope it works. Check out Trust My Mechanic instructions on you tube. He has a high success rate with this product. Good luck. Update sealer failed after a few weeks of use. Would not buy again. Looks like no short cut in these kinds of situations. I wound up just buying a used engine and rebuilding it. Then replaced the one in car with it.

  3. AJ

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    I honestly didn’t really expect it to work but it was worth a try

  4. Grizzley

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    This item arrived on time and was just what I needed to seal my leaking rad.

  5. Zac

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    I have used this product one time in my 2007 Toyota Tundra to stop a radiator leak coming out of the coils, following the directions carefully and allowing it too cure it worked. I have driven about 20,000 miles so far and the leak hasn’t came back. Trying this a second time now on my 2013 yukon so hopefully the same result. I do not have any experience with it helping a head gasket leak.

  6. Quanxing Zhang

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    I used the this product twice and finally it worked.First time, I followed the instructions blindly without paying attention to capacity. I mixed it with 3 quarts of water. But I was only able to put half the solution to the radiator because my car has small capacity. So after doing all the things, My cars is still loosing coolant.After thinking it over, I decided to give a 2nd try. This time I mixed it with less water so I managed to put the whole can of k &w into cooling system. After going through all the procedures according to the video, it finally worked.Now I hope it will last a long time.

  7. superdave

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    I have used this product for over 40 years. WATCH the video on “how to use”. It is a great product. Not to be used with ANY anti-freeze, JUST WATER and make sure the engine is hot/operating temperature. After you drain the system, let it set up for at least 2 days. This is the difference between this product and all the other crap out there. This is a good fix, not a band-aid.

  8. Jeff Hawkes

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    it worked to seal my leak but my bottle showed up almost completely dried out. Had to bash it with a screwdriver to get it out of the bottle and then beat it into submission to mix it into water before use.

  9. Customer

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    It was my third and final attemp to fix my head gasket. My friend told me about this product and how well it work. We followed the direction to a tee. Sealed up perfect no leaks to this day. Thank You 😊

  10. Rickp

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    After lots or research, I settled on this product, prepared me vehicle and waited for a week for it to show up. When it arrived I followed the instructions to a tee, when I opened the can and poured it into the gallon just, after vigorously shaking it as per the instructions, the business part of the product had solidified in the bottom of the can rendering completely useless. DO NOT WASTE YOUR MONEY

  11. Dave

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    Good product to return.

  12. Rachael Luby

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    Works

  13. Dustin V.

    Imported from Amazon. This is not a review of a purchase made on this website.

    External marketplace context: Verified Purchase

    Seems to work. I let car run for 3 hours and water in oil evaperated. Do what the can says.

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Product facts

Specifications

Canonical product
MP-US-B000CIPV5E
Source product ID
B000CIPV5E
Category
Car Care / Fillers, Adhesives & Sealants / Sealants / Radiator
Available images
1

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Specification notes

  • Canonical product: MP-US-B000CIPV5E
  • Source product ID: B000CIPV5E
  • Category: Car Care / Fillers, Adhesives & Sealants / Sealants / Radiator
  • Available images: 1

Before you buy

  • Match the complete identifier, side, position, connector, dimensions, and visible design with the existing part.
  • Treat uncertain vehicle notes as a buying aid, not as a confirmed fitment guarantee.