What does Blue Devil Fix?
It permanently seals cooling system leaks such as radiators, heater cores and freeze plugs. It also permanently seals most blown head gaskets, cracked heads, warped heads and cracked blocks.

Is it safe to use Blue Devil in my vehicle?
Yes. Blue Devil is safe to use in all water-cooled systems. It is non-clogging and is 100% chemical. It does not contain any filings or pellets that can plug up radiators.

How much product do I use?
Follow the usage on this chart:


Do I need to flush the cooling system?
Yes. Flush the radiator and cooling system with a flushing agent after removing the bottom radiator hose. Flush thoroughly a second time with water to remove all traces of agent.

My car is overheating. Will Blue Devil correct this?
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.

How does it work?
Blue Devil reacts to temperature differential created by airflow at the leak point. That temperature differential is the catalyst for the chemicals in Blue Devil to react and form its chemical weld.

I don't want to replace the fan switch if the head gasket won't be repaired by Blue Devil. Must I make this repair first?
Yes. All cooling problems need to be fixed first. Even if you replace the gasket these problems need to be addressed.

How long will the repair last?
Blue Devil PERMANENTLY seals leaks.

What are the tell tale signs of a worn or leaking head gasket?
• A rough idling engine with large amounts of vapor coming from the tailpipe
• Loss of coolant without an external leak and carbon deposits inside the tailpipe
• Bubbles in the radiator

Will Blue Devil prevent a gasket from blowing?
No. There are no preventative claims made for the product.

My freeze plugs are the soft type. Will Blue Devil work on them?
Yes, Blue Devil will seal leaks in all types of freeze plugs.

My thermostat is hard to reach. Do I really have to remove it?
Yes, Blue Devil must be applied to a free flowing system.

Does Blue Devil work on plastic heater cores?
Yes, it is suitable to repair all types of leaks in all types of heater cores.

Are there any applications where Blue Devil will not be effective?
Blue Devil should not be used to seal seam leaks in radiators or heater cores.

Will Blue Devil work on aluminum engines?
Yes, Blue Devil will bond to all metal types-aluminum, steel, cast iron, even plastic cores and tanks.

Will this product knock me out of an engine job?
No, the application should be used for those customers who are unwilling or don’t have the money to spend on a car what would not justify the expense.

Will you guarantee your product to work?
Blue Devil will work when the diagnosis is correct and it has been used in accordance with the directions.

I tried the product and my radiator has a white crystalline deposit or jell, what is this?
These are telltale 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 form in the passages of the core. Sometimes the old fluids will jell or crystallize and can be seen in the system. To remove these deposits flush cooling system using a flushing agent or a flushing machine.