VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 radiator leakage

Hello!
My 37 Chevy radiator is leaking at the fitting.
It seems that the fitting is (malleable) cast iron.
So is it soldered or brazed into the water tank?
Why did GM used (malleable) cast iron for this?
Thank you!
Tino

It is soldered and I have no idea why GM used such a heavy connection. The only thing I can think of is that they were concerned with flexing in that area causing leakage so the heavy metal was used.

I think this type of radiator hose is not flexible enough and caused the crack.This hose is short (6") and stiff
Tino

Hey! What's wrong with 6 inches???

The hose becomes more flexible as it gets hot. Dunno if accordion-shaped hoses were used when new?

I was also wondering why the top outlet is made of much thicker metal than the bottom. Maybe the thinner metal cannot withstand the constant movement of the engine while the radiator stays put....and the top of the engine moves more than the bottom.

I think its a combination of the stiff hose and the short length that caused the problem.
Maybe the hose is more flexible when the water is hot but what should i do till the water is hot? Idling?
So it would be better to find a more flexible hose for such a short length.
The installed hose is made for modern pressurized cooling systems.
Tino

You have it all figured. They used a cast pipe simply because it was the cheapest way of doing it and the strongest. I agree that the hose that you have fitted is too stiff. Such stiff hoses are fine down the bottom where there is suction that causes a soft hose to collapse and very little engine movement. Up the top the engine moves a lot and the hose is only under mild compression. The upper hose on my 38 is quite soft with a woven cloth outer.

Tino...Sorry about that...I was joking about the 6 inches. Here in the USA we tend to make jokes about something not being long enough....if you know what I mean....

Still, you are right about it being too stiff. Some things should be stiff, while others should not.....

the top tank can be taken off and the outlet and tank both cleaned and then soldered back in place. Not too difficult a job for a radiator shop.

Radiator should be boiled and rodded whilst you have the tank off.

If all else fails, contact me. I think I have a NOS one upstairs in the garage. It won't fit a 41 so I won't be needing it. I'm pretty sure it is for a 1937 but may be for a 1/2 ton pickup. I'll have to check.

BTW: The regular inch and a quarter (1 1/4) upper hose does seem a little stiff but it will flex enough that you shouldn't have to worry about it snapping off. Stating the obvious, Your's has fatigued to the point it has started leaking. A rare failure.

Best,
Charlie

Thank you guys!
First I´ll try to fix it.
If i fail there is a radiator in our street.
Tino