Help - Radiator Expansion Tank Leak

It seems that over the winter, my 1972 246 GT (U.S.) developed a pin hole leak along the vertical seam of the radiator expansion tank. I just discovered it while warming up the car the other day. Specifically, it is midway up on the passenger side, right on the seam. My hope is that this can be repaired with a proper weld rather than having to source a replacement tank. Can anyone confirm who might have experienced a similar problem? With Spring approaching, I would like to get this resolved in the next week or so. Thank you in advance for any suggestions.

 

Any decent radiator repair shop should be able to solder it up. Good Luck.

 

Agreed. A good shop will also pressure test it for other leaks which may not yet be spurting fluid but are showing signs of weeping.

 

Tank is brass with soldered joints. Any competent radiator shop should be able to resolder the joint and pressure test the assembly. Should take an hour or so and not be expensive. Just paint black again and you should be fine for years.
John

 

I think the early tanks were brass and the later ones steel. They should have made all versions brass. The seam differentiates the two. Try a magnet on it if you are not sure.

 

Later are Steel.
G P

 

I had the same problem, and after two failed weldings of the expansion tank in six months I just got a new one from Superformance and that was the end of the problem.

Based on my experience, I would just get a new one. They are not that expensive.

Cheers,

Julio

 

After resoldering the leaking lower seam on my (original brass tank from my Euro '69), I paniced and bought a new one (PM me and I'll give you the name of the supplier). The quality of the new one was so poor I elected to have "my guy" take the old one completely apart and totally reweld- end of problem (so far). Now I have the other as a spare- hopefully will never have to use it. Agree with others that any competent radiator shop should be able to do the job; they can push out any existing dents while it's apart too.

 

Removed expansion tank without too much difficulty and confirmed it is the earlier brass type in overall excellent condition. I will take it to a radiator repair facility Monday or Tuesday and should be on the road for next weekend. One question, however: the overflow tube simply routes to the bottom of the car and to open air. Am I correct that there is no catch container? I am more familiar with early 911's where this is not an issue!

 

You are right, no catch container. It's an Italian car. What is one more spot on the garage floor?
John

 

John (or other DIY enthusiast):
Is there a particular lubricant you would recommend to refit the coolent hose to the expansion tank? It's a tight fit and I would prefer to to be out driving this weekend rather than struggling with it in the garage. Thanks!

 

Liquid Soap?

 

Dawn works but don't use much. Coat inside of rubber tube and outside of fitting. Q-Tip works well as applicator. You don't want bubbles. Silicone grease is perfect if you have access to some. Doesn' hurt anything. Used on O-rings and as a thermal transfer grease in some electronic systems. Pool/Spa supply shops and electronic shops are good sources. Probably shouldn't use the white Silicone grease that is sold as heat sink compound. White filler kills lubricating qualities. Use the clear stuff. Also sold as heat sink compound. Good luck.
John

 

Saliva worked well when I did mine.

 

Vaseline works great for all hoses.