Fixing radiator

[Birch Hill Farm]

I have an old international 444 tractor with a brass radiator. It is leaking along 3" of the seam between the top and bottom parts of the reservoir tank. There is no direct fit replacement radiator available for this tractor so, the only option is to fix this one or modify a radiator from a close model to the 444. I was thinking of cleaning up the seam and soldering it with regular plumbing solder or use some of the sticks of silver solder that we use in A/C systems. Will this work? what kind of solder should I use?
here is the seam in question:

[Bigfoot62]

I'm not an expert on radiators or soldering. I carry mine to a pro.
Had the same thing happen with the bottom tank. I watched the guy as he completely removed the tank from the core, cleaned the entire joint and then re-soldered.
He said that you can't just patch a crack like that. You need to do the whole seam.

[Birch Hill Farm]

Makes sense, I assume I could heat up the joint to separate the two parts?

[Bigfoot62]

Makes sense, I assume I could heat up the joint to separate the two parts?

That's what he did. I think, though, you have to be careful not to apply too much heat. You don't want to melt the solder that holds the core together.

[Birch Hill Farm]

Thanks for the reply! Any thoughts on what kind of solder would be best?

[Steave]

I agree with Bigfoot62.

I have lucked up and temporarily repaired a leak but most of the time only created more.

Maybe you could try liquid solder in a tube. I usually don't have much use for stuff like that and never used it on a radiator but might be worth a try. If by any chance it did hold sure would save you a lota work.

[Bigfoot62]

Thanks for the reply! Any thoughts on what kind of solder would be best?

Don't know for sure. IIRC, he used a long "stick" of solder, so I'm guessing silver solder.
You might want to post that question on the welding forum.

[Birch Hill Farm]

Thanks for the reply, I tried posting in the welding forum but, never got a response.

[cyrush]

The radiator when manufactured would be soldered with the ordinary lead/tin variety.Do not use silver solder as this needs a higher temp to melt and you stand a good chance of loosening the core joints with the heat transfer.
Best lob would be to pay the extra and get a professional repairer to do it for you ???

[Birch Hill Farm]

I just hate pay someone to do a job that I could probably do my self.... Good thought on the silver solder an 1800deg melting point might be too much for the old radiator.