Radiator & Block Sealer

Radiator & Block Sealer


Radiator & Block Sealer

Part: # 00205 | Size: 16 oz. |

Any product purchase made through Ebay will be VOID of all guarantees and ineligible for warranty through BlueDevil Products. Sellers on this third party retail site are unauthorized and are not verified partners of BlueDevil Products. If you have any questions about your online purchase, please call 888.863.0426 before ordering.

BlueDevil Radiator & Block Sealer is an easy-to-use formula that will repair and seal leaks in radiators and/or engine blocks. It does not contain solid or fibrous materials and will not clog or harm cooling systems. It will bond to plastic, cast iron, aluminum, alloy or metal. BlueDevil Block Sealer is compatible in gasoline and diesel engines. It is a guaranteed permanent radiator sealer.

  • Permanent repair for radiator and block leaks.
  • Works effectively on plastic, aluminum and/or metal radiators
  • Contains no solids or fibrous materials.
  • Safe and Easy to use.
  • ASTM D1881 & ASTM D3147 Compliant


Directions: BlueDevil Radiator & Block Sealer



NOTE: Dirty or clogged cooling systems should be chemically flushed before installing BlueDevil Radiator & Block Sealer

  1. IMPORTANT: When engine is cold, remove radiator cap.  ENGINE MUST BE COLD TO AVOID SEVERE BURNS.
  2. If radiator is full, drain enough antifreeze to allow space for BlueDevil.  If the vehicle does not have a radiator cap, product may be installed through the top radiator hose.
  3. IMPORTANT: POUR SLOWLY!  Starting with a cold engine and the heater on maximum setting, slowly pour BlueDevil into the radiator as the vehicle idles.
  4. After installing BlueDevil, replace radiator cap. Allow vehicle to idle for 45 minutes with the radiator CAP ON and BlueDevil in the system
  5. Top off radiator with clean antifreeze or water. BlueDevil can remain in the system.

CAUTION! Keep away from children and avoid eye or skin contact. If eyes or skin become irritated, rinse with cold water immediately. If swallowed, drink large volumes of water and consult a physician if discomfort continues.


If you have further questions in regard to the proper application of this product, please call 1.888.863.0426 to speak with our Tech Department.

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Just wanted to take a few minutes to let Team BlueDevil know that I was extremely pleased with the product. I recently used a 16 oz bottle of BlueDevil Pour and Go Radiator and Block Seal on my 2014 Dodge Ram 1500. I followed the directions to the “T” and just like that my problem was solved. Thanks Team Blue Devil!!!!

– Andy A.

Fantastic Product!

I just wanted to tell you how much your product has helped me save money. I bought a van last year from a man who bought it for his business but he said on the way to get gas it started smoking real bad and then it died so he put it in the paper for sale lost big on it. I bought it for $500.00 thinking I’d have to replace the motor started messing with it a little found it needed a starter that’s why it won’t start so replaced it and it started but smoked bad white smoke I checked on a few products seen Blue devil for block seal followed the instructions 50 minutes later it stopped smoking and have been driving it ever since. Just wanted to tell you all that it works great.

Thank you, Charles


It permanently repairs leaks from a radiator and/or block.

No. All cooling related problems must be solved first. Defective fan switch, fan clutch, clogged or restricted cores, heavy scale and sediment deposits, or systems jellied from antifreeze must all be properly functioning and capable of adequately cooling the vehicle.

BlueDevil Radiator & Block Sealer reacts to temperature differential created by airflow at the leak point. That temperature differential is the catalyst for the chemicals in BlueDevil to react and form a chemical weld.

Yes, BlueDevil Radiator & Block Sealer is compatible with all types of antifreeze.

For best results, BlueDevil Radiator & Block Sealer should not be poured into a reservoir or overflow.  If you do not have direct access to the radiator you should, with the vehicle off and cold, disconnect the top radiator hose and pour the product directly in.  Reattach the hose, tighten the clamp and continue with the rest of the directions.

No, BlueDevil Radiator & Block Sealer is an easy-to-use formula.

BlueDevil Radiator & Block Sealer creates a PERMANENT seal.

No, BlueDevil Radiator & Block Sealer should not be used as a preventative maintenance.

Yes, it is suitable to repair all types of leaks in all types of radiators.

No, the product may be left in the cooling system.

BlueDevil Radiator & Block Sealer is guaranteed to work when the diagnosis is correct and it is used in accordance with the directions.

No, the application should be used for those customers who are unwilling or don’t have the money to spend on a car that would not justify the expense.

BlueDevil will work when the diagnosis is correct and it has been used in accordance with the directions.

These are tell-tale signs of a radiator that is in need of service. When fluids are not changed often enough under severe operating conditions or in areas with hard water, scale deposits may form in the passages. Sometimes old fluids will jell or crystallize and can be seen in the system. To remove these deposits flush cooling system using a flushing agent and/or a flushing machine.