MTFCA Forum

The condition of my coupe radiator is shown in the attached photos. It looks good to me, but the outlet is severely rusted. What do I need to do to it?

I see no visible problems. Rinse it out with a garden hose and give it a try. It may work well, or it may not. Handle it with care. It may have clogged tubes, leaks, loose fins, or any combination of the preceding. Or it may not. If you want to be sure of good results,and perhaps avoid having to take newly-painted items off the car if the radiator doesn't prove out, and perhaps avoid wasting money on inexpert repairs, buy a new radiator. I would keep that radiator, in any case.

Bruce, if it don't leak, don't fix it. That bottom outlet is cast iron, quite thick. I have seen holes soldered, [read soddered] up to stop leaks. The hose mounting service looks quite good, so it should seal nicely. When it does rust out, a cast brass replacement is the best fix, if the radiator cools well.

A competent radiator shop would remove the bottom tank, fit the outlet to it and replace the assembly.

Allan from down under.

I bet there are 50 members who would rather have that then the one they have. Besides there are none to buy... Berg's stop making them and I believe Brass work's is backlogged and $$$$. Expect powder rust in the cooling system if only water is used and no additives to prevent it. Upper Iowa calls for anti-freeze and has additives . Fear the flaky stuff that can clog passages etc.

Bruce that radiator looks great, use it as is. I apply a thin film of non-hardening gasket sealer 2b on the hose connections or they will leak.

It’s a good looking radiator and as others stated don’t try to fix it! The bottom outlet looks really good. Good for many more years. Rinse out the radiator with a hose and go for it.

The question is will it cool? Not leaking is only part of the problem. If it cools is the real question.

Dan Hatch wrote: ↑

Fri Mar 18, 2022 9:33 am

The question is will it cool? Not leaking is only part of the problem. If it cools is the real question.

I agree. I would do a minimum installation, fill the system with water, and run it. I would not complete the installation (hood, radiator shell, etc untill you establish that it cools). There are few T - related issues that are more of a PITA then constant overheating. If the radiator doesn't cool, your option is to either find a radiator shop that can get a flat-tube core and install it, or find a new core yourself and have a radiator shop do the job. Do not purchase a used radiator - there is a reason that it is for sale. No T lover would sell a perfect radiator.

If it was mine I would seal up the filler neck (O ring and cap), lay it down on the front and pour in a gallon or two of cheap vinegar and let it sit for a day or so. Then flush it out and reinstall.
Once I was satisfied it wasn’t leaking I would fill the system with at least 30% antifreeze to reduce the corrosion!

That appears to be a well-made, flat tube replacement radiator. It may not be anywhere near as old as the car, and it appears to have suffered no abuse. The corrosion on the cast iron outlet is of no consequence. I'd rinse it out and give it a good trial run as suggested above. Handle it with care.

Just sitting running at an idle will not test a radiator. I have seen them that would idle all day not over heat. But drive down the road a half mile and they would blowing steam like a tea kettle.
I will not even look at used radiators unless they are cheap, like scrap price.

I wasn't very clear when I said, "What do I do to it?"

I meant, what do I do to the corroded cast iron outlet? Is there a way to "smooth" it out?

It has a round tube core. Which is best, a round tube or flat tube radiator?

BLB27 wrote: ↑

Fri Mar 18, 2022 2:30 pm

I wasn't very clear when I said, "What do I do to it?"

I meant, what do I do to the corroded cast iron outlet? Is there a way to "smooth" it out?

It has a round tube core. Which is best, a round tube or flat tube radiator?

Only clean off the loose stuff. A wire wheel on a drill or die grinder. If pitted severely, (doesnt look bad at all) put a thin layer of ultra black silicone to fill the pits during assembly.

To answer your question about which is best round or flat tube it depends what you want to do with your car I think.
If your a purist and want to be original as you can be you would want a round tube. But in the late T’s case Ford did have a flat tube in some of the late T’s.
A flat tube radiator is an alternative for most T’s and folks that use their T for driving want a flat tube and lots of folks think they cool just as good better than a round tube.

Round or flat tube gets into whose opinion you listen to! The same thing goes for which oil, transmission band type and a few other things.
Welcome to the world of Model T’s!

If your radiator turns out to be one that looks good but doesn’t cool getting a flat tube recore is the way to go. But that’s my opinion!

Go to resources and then go to the old version of the encyclopedia and you can get good information about the evolution of T radiators. Ford used some flat tube style from 24-thru 26 according to the encyclopedia.

My '27 was built in March and had a round tube radiator that didn't leak or cool. If there were any late Model Ts that had a flat tube radiator, they must have been real late and damn few.

A question which hasn't been asked is this: How did it cool before the car was torn down for repaint? The answer to that would be key in knowing how it will cool after the car is repainted.

The coupe had not been run since 1960.

I should have added that I believe it did not have a heat problem then, but that is long time to remember!!!!!!

Loss of ability to cool is more of a time problem as a use problem. The older a radiator is the more likely it to lose the ability to transfer heat from tube to fin. And it maybe worse it said radiator is not used from a long time.
The ones I have seen that had that problem were ones that had been sitting for a old time not being used. Good luck with your radiator.

To answer your question on round-tube vs flat-tube, If you are going to be serious about showing your T you really need a round-tube. If you are planning to use the car as a driver and on tours, you need a flat-tube. The flat-tube radiator has almost twice as many vertical tubes and does transfer heat better. If you have an original round-tube, I'll bet that you will be flirting with overheating on a regular basis. Even if that old round-tube radiator will cool, I'd still be putting a few shekels in a jar labelled "flat-tube radiator" on a regular basis.

One advantage that the radiator has going for it is the climate that it will be used in: Its not in the South