BlueDevil Products00205 Radiator & Block Sealer - 16 Ounce

Works advertised. Great product and value.

I used blue devil because of the comments. My water pump went out on me and cracked the block right behind water pump due to over heating. After replacing water pump and putting blue devil in the radiator I watched a spray of water go from spraying water out to a trickle and then to nothing and the heat on the motor dried up all moisture. Drove my truck up the road about 8 miles and back with absolutely no issues. I’ve never seen any product work like it says it does. Blue devil does work. It took 45 minutes like it said but every time the thermostat cycled the leak got less and less. It’s unbelievable it actually sealed a cracked block.

Great stuff

Worked well for my radiator leak.

Disappointed in the product. It didn't work at all. I still have a leak in the block. It had high ratings which gave me hope that it would work... not the case here.

This is one of the best products ever, It took the place of having to weld and it sealed the hole that was a nuisance wish I had known about this product beforehand as it could have saved me plenty of time in radiator repairs.

Honda Civic, hairline crack in cylinder wall, had block and head milled EXACTLY flat, new head gasket too. After calling and talking with a technician there, I used High Temp JB Weld on coolant side of cylinder tube after routing a 1/16th inch slot along the hairline crack and cleaning with acetone, let that cure exactly per directions. Then I used Blue Devil product exactly as specified. It worked for two days. Not a minute more. New short block the expensive answer. Previously, on a Cadillac NorthStar engine, Blue Devil worked perfectly on a bigger crack through the outside of the engine block into the water jacket.

This product saved me a ton on money!!