Rod it or Replace it?

[JBog]

Is it worth it to attempt to have a shop rod out a round tube radiator or just save up the allowance money and buy a brand new brassworks radiator?

[Rich Eagle]

If they know what they are doing and don't charge too much they might be able to save it. How is it otherwise?
Rich

[JBog]

If they know what they are doing and don't charge too much they might be able to save it. How is it otherwise?
Rich

It's not leaking, but it recently started overheating in the last month after no trouble at all. I flushed the radiator and block/head and it's still overheating. It just started happening after my 6th parade of the summer. Went through all 5 parades at low speeds with no overheating, and on the drive home from the 6th, it just decided to overheat, boiled off all its 50/50 mix, and stalled on the side of the road.

Head gasket and engine looked fine, so I cleaned it up and put it back together, flushed it again and it still overheats after only a few miles.

I didn't want to shell out 1K on a new radiator, but if it's a waste of time and money to rod it out, I'd rather save some of both by not bothering.

[speedytinc]

Maybe.
If there are no or few leaks & its only a clogged tube issue then probably yes.

Decades ago I had a 23 radiator that was running too hot. I was ready to buy a new one, but got the idea to investigate further. Them fancy temperature guns were quite uncommon, but I could feel that only the center third was hot. I figured I had nothing to loose, so I removed the bottom tank. I found a lot of clogged tubes. I cut some long strips of anodized aluminum & commenced to "rodding" the tubes. Got them all flowing with only 1 leak to fix. Soldered it back together. Cost nothing & this same radiator gave me another 20 years of trouble free service.

I have seen ,all to often, where rust flakes plug the tops of the tubes. Turning the radiator over & applying pressure water & air can loosen them up.
Look down @ the few tube openings you can see to access the reason for the clogs. If its plugged with mineral deposits, a chemical cleaning might be in order.

[pron022020]

If it is original I'd say save it.

[TXGOAT2]

Take the radiator off the car and turn it upside down and back-flush it. Do it over and over, shaking the radiator between flushes. A device that connects to a water hose and an air pressure line is best. Don't pressurize the radiator. It probably has rust flakes in the tops of the tubes. If it hasn't been overheating for a very long time, they may not be stuck tight. Go over the car and make sure that nothing else is causing it to overheat, like dragging transmission bands, dragging brakes, leaking head gasket, cracked block, late timing, clogged oil pipe, and so forth.

[Russ T Fender]

If it is just clogged tubes it is definitely worth rodding it but if it is an original radiator and the tubes are not making good contact with the fins rodding will not solve the problem. Not sure how you can tell but if it looks to be OK I would give having it rodded a shot and if that doesn't work you'll know why.

[John kuehn]

Spend your money one time on an original round tube and that’s it. More than a few original radiators have been bought at swap meets that looked good but the performance was a different story. You might get lucky but the odds are against it. After nearly 100 years things begin to change on a radiator if it’s been on a car and been in service.

[Rich Eagle]

Rodding it out may produce some leaks. I rodded one out myself and it is the best cooling radiator I have. However some are just rotten inside. You can't tell unless you try and we can't know how it will turn out.
I'm hoping for the best for you. Let us know.
Rich

[ThreePedalTapDancer]

Mine was clogged, so I took it off and closed off the hose openings and filled it with evaporust and let it sit for a couple of days. It dissolved the rust and I flushed a ton of black goop out, and it worked fine again.

[Craig Leach]

I have been using Zepp calcium rust & lime remover with good results and know some that swear by evapo-rust. I pour the Zepp in straight with the radiator out. Plug the overflow & put hoses on to get the level high enough to fill it completely. I also do the same with blocks & heads. I have left it in radiators over night & blocks & heads for days. pour it back on the jug for the next time. ( don't pour it out on the grass or near any shrubs or trees) Then vigorously flush with clean water in both directions. I have known some that run the Zepp & the evapo-rust in the cooling system for a while to clean out the entire cooling system. There has been a lot of stories of cars that suddenly start over heating, doesn't the steam holes plugging up cause that ? If you have any rust stopping leaks either product will remove it & you will have a leak. But I contend it was going to leak at some time anyway.
Craig.

[John.Zibell]

If it is an old radiator, the fins may have lost contact with the tubes. If that is the case, nothing can be done to save it. Best option is to find an old school radiator shop that can do a re-core if the fins have lost contact, or just bite the bullet and purchase a new flat tube radiator.

[Craig Leach]

John is correct about the fins being loose. Has anyone pursued thermal heat transfer coatings for radiators. They have them for industrial heat transfer applications such as heat exchangers.
Craig.

[Jerry VanOoteghem]

Seems very odd to me that, "all of a sudden", you have an overheating issue. To my thinking, radiators don't just "go bad", like a burned out lightbulb. I suppose they could gradually degrade until they reach a "tipping point". Have you noticed things getting increasingly warm? Have you peeked inside to see if maybe the baffle plate in the upper tank has broken loose and is now laying over the tops of the tubes?

[speedytinc]

Seems very odd to me that, "all of a sudden", you have an overheating issue. To my thinking, radiators don't just "go bad", like a burned out lightbulb. I suppose they could gradually degrade until they reach a "tipping point". Have you noticed things getting increasingly warm? Have you peeked inside to see if maybe the baffle plate in the upper tank has broken loose and is now laying over the tops of the tubes?

"The all of a sudden" fits the rust flakes plugging the tubes(thats how my most recent overheating problem went), not the old radiator that lost its fin cooling ability from age or the slow buildup of calcium deposits.

Definitely peek inside.

[Scott_Conger]

Head gasket and engine looked fine, so I cleaned it up and put it back together

being that pulling the head is such a popular thing to do, I am genuinely curious as to what you expected to find?

A compression check is fast, cheap and easy...saving time and risk of pulling the head and using up a head gasket if the old one is compromised in its removal. And as others have said, with the exception of the top baffle plate falling off and blocking the top of the tubes, radiators don't go bad fast. I would suspect a baffle problem, a timing issue or since you've done a bunch of parades and low-band driving, you may have a failing band bunch up and drag on a drum (can happen with old cotton bands if they have a rivet or two pull out).

[JBog]

Seems very odd to me that, "all of a sudden", you have an overheating issue. To my thinking, radiators don't just "go bad", like a burned out lightbulb. I suppose they could gradually degrade until they reach a "tipping point". Have you noticed things getting increasingly warm? Have you peeked inside to see if maybe the baffle plate in the upper tank has broken loose and is now laying over the tops of the tubes?

"The all of a sudden" fits the rust flakes plugging the tubes(thats how my most recent overheating problem went), not the old radiator that lost its fin cooling ability from age or the slow buildup of calcium deposits.

Definitely peek inside.

I didn't notice any gradual warming, I was in all of the parades for Cheyenne Frontier Days and the car always finished strong, it wasn't until driving home after another parade that it just overheated.

[JBog]

Head gasket and engine looked fine, so I cleaned it up and put it back together

being that pulling the head is such a popular thing to do, I am genuinely curious as to what you expected to find?

A compression check is fast, cheap and easy...saving time and risk of pulling the head and using up a head gasket if the old one is compromised in its removal. And as others have said, with the exception of the top baffle plate falling off and blocking the top of the tubes, radiators don't go bad fast. I would suspect a baffle problem, a timing issue or since you've done a bunch of parades and low-band driving, you may have a failing band bunch up and drag on a drum (can happen with old cotton bands if they have a rivet or two pull out).

Hey Scott,

My concern at the time was the fact that it had managed to boil off nearly all of it's coolant and then stalled out. I got really worried that either the head gasket had blown, or that I had piston and/or bore damage - my pistons are aluminum (came like that when I bought it) and the head is also aluminum (Z head).

I had not thought of the bands, I put new Guinn cottonwood bands on this past Spring, I'll open it up and take a look at them and make sure they aren't rubbing/dragging.

[Scott_Conger]

drain the radiator some and fish around with a coat hanger...I bet as Jerry said, the top baffle broke free in the header tank and is now laying across the tubes...been there, done that, in our '15'.

Once I found it, I made two little hooks which holds it up and suspends it from inside the neck. Has worked fine for last 3 years and kept me from unsoldering an original radiator. Maybe I'll fix it right, someday, or maybe not. I have 4 cars and am not particularly worked up over a car which runs like a top but isn't "right".

good luck.