Slight water leak at head gasket below water pump

[BRENT in 10-uh-C]

Well, this question is about like asking which new pickup truck is better, -a Ford or a Chevrolet.

I typically use a product made by Irontite that is a ceramic sealer since I am sealing Head Stud threads or Gaskets -and not the Radiator. (I typically think of Bars Leak as a Radiator stopper-upper since it has ground-up copper particles)


IMO, the issue you want to make sure you do first is get all of the organic stuff out of the cooling system (oil, water pump lubes, antifreeze, etc.) where the sealer can actually seal. Since we are using the sealer on fresh rebuilds that has clean water jackets, ours is more of a surefire thing.

Likely most of the parts stores with have those K-Seal, or Blue Devil, or whatever Head Gasket Sealer meant for sealing cracked cylinder heads and blown head gaskets, so any of them is probably going to successfully do what you need. I would start by draining any coolant and then add Dawn dishwashing liquid to water and run the engine to circulate the soap so it will breakdown any greases or oils. Most of those Head Gasket wonder products likely have a flush they recommend that I would use to follow up the soap flush with. When you get ready to add the sealer, I would take a small piece of fuel line that you can slip over the radiator overflow tube. Stick a bolt in the opposite end of the hose to basically plug air escaping out the tube. What this will do is add pressure to the system (2-3 lbs) which will help force the sealer into the seeping area. Once you have run the engine for awhile (we typically run them for about an hour on our run-in stand after retorquing the head gasket). At that point, drain the coolant with sealer and then thoroughly flush the Radiator separately to get any remaining sealer out of the tubes so it won't plug the tubes. Then let the block sealer dry overnight, and you will be good. I'm sure there are other ways too, but this has worked well for us.