The Ford Barn

mcgarrett · 05-18-2026, 03:00 PM

Need recommendation for a good stop-leak product. Here are the details:

I've been working on getting a '30 Coupe (not mine) in running condition again after sitting for roughly 40 years outdoors.

I have it running and driving and the engine sounds remarkably good. After running for an extended period of time, a slight coolant leak has developed just below the newly replaced water pump at the gasket line. Looking at it a little closer, I noticed both of the nuts holding the water outlet on the head were not tight to spec compared with the other head nuts. I tightened both up and the leak has slowed considerably, but seeps a little more when the engine cools down. Since the car has been out in the weather for so long and head nuts are VERY rusty I don't want to run the risk of breaking a stud by replacing the head gasket...

So I'm wanting to try a good quality stop-leak, if there is such a thing to see if it will stop the leak without removing the head. What would the experts here on the Barn recommend?

05-18-2026, 03:00 PM	#1
mcgarrett Senior Member Join Date: Dec 2013 Location: Corsicana, Texas Posts: 1,551	Slight water leak at head gasket below water pump Need recommendation for a good stop-leak product. Here are the details: I've been working on getting a '30 Coupe (not mine) in running condition again after sitting for roughly 40 years outdoors. I have it running and driving and the engine sounds remarkably good. After running for an extended period of time, a slight coolant leak has developed just below the newly replaced water pump at the gasket line. Looking at it a little closer, I noticed both of the nuts holding the water outlet on the head were not tight to spec compared with the other head nuts. I tightened both up and the leak has slowed considerably, but seeps a little more when the engine cools down. Since the car has been out in the weather for so long and head nuts are VERY rusty I don't want to run the risk of breaking a stud by replacing the head gasket... So I'm wanting to try a good quality stop-leak, if there is such a thing to see if it will stop the leak without removing the head. What would the experts here on the Barn recommend?