Lately, I had been noticing coolant on the bottom of the radiator support on the driver side of my '72 Supreme. Didn't think it was a leak at first cuz she hasn't been running any hotter than usual (200 deg all day long). I had also noticed a small drop in the radiator level, but figured it was just going into the reservoir, as the level was normal there.

Today I looked into it deeper, and discovered I do on fact have a pinhole leak. It's coming from the top of the radiator on the driver side, thus explaining what I was seeing on the bottom.

As I said, no issues with overheating, and it's not enough of a leak to cause any other issues.

Will continuing to drive it cause bigger problems, or will I be ok for now until I can get it repaired? It's the original radiator that has been re cored, so I'd like to keep it if possible.

What should I do?

 

Where on the top of the radiator - exactly? It might be emanating from the large O-Ring in the channel on top of the radiator where the upper tank mounts to the radiator. If you had the radiator re-cored they would have removed the upper tank and resealed it with a new O-Ring; although I think some shops might make there own O-Ring - I'm not sure. It's possible the radiator (cores & fins) aren't leaking but instead the upper tank seal might have crimped during the install or something to that effect. If it truly is a very minor nearly negligible pin-hole drip, I'd drive it until you decide to do something otherwise.

 

It looks like it's about 1/2" down from the upper corner Norm. The re core was done by a PO, so not sure exactly how long ago, but I would guess going on 3 years now. Based on the documentation I have, he didn't drive it much, and this started about a month ago.

When I fill the radiator, the level drops to about 2" from the top and seems hold steady at that point, and it maintains about 2" in the reservoir, so that's why I'm not too concerned at this point. I was just concerned that it would get worse.

 

It sounds like it's around or near the upper tank or the seal around or near the upper tank. I recognize you just installed an aftermarket overflow reservoir and if the radiator is maintaining what is normal - about a 2" level below the top - you're going to be fine. Obviously you'll keep your eye on it. That O-Ring seal is held to the top very tightly and I suspect won't loosen any further, but it's anyone's guess.The O-Ring may have been crimped during the re-install of the upper tank.

 

Norm, you are describing a newer model aluminum radiator with plastic end tanks (actually you said upper tank). The original radiator is a copper-brass unit so the end (side) tanks are soldered to the core. Minor details, but as you said, it should be OK to drive.

The leak is likely at the solder joint between a tube and the end tank, or maybe even in the tube itself. Over the years I have driven cars with all sorts of coolant leaks, just check to ensure the coolant level doesn't get too low. Just be prepared and carry a jug of water in case the leak gets bigger.

 

Thanks and will do 👍

 

Kenneth - Indeed, valid points you indicated; I thought a PO to Dave replaced the radiator with an aluminum radiator from discussions w/ Dave a couple years ago since I thought his car used to be a race car and the PO was reducing weight or whatever. I didn't feel like looking up the prior discussions.
Dave you can validate. I thought it was around the time when we were discussing those angled braces from the firewall & the switch you or the PO put in next to the radiator top plate? Do you have the original style or a newer aluminum? At any rate, it should be OK.

 

I researched some posts/threads & the thread I was thinking about were actually two threads: (1) The thread regarding the original radiator leak and (2) The thread regarding the aftermarket trans cooler; and, I still don't know which radiator you have. LOL But it may have been that discussion regarding the aftermarket trans cooler which made me think you had a newer style aluminum radiator. Cheers Dave!

 

Back at ya Norm... and it is the original copper (or brass?) radiator, hence my wishes to keep it😀

 

Back in the 70's I worked in a radiator repair shop. We would pull the tanks, rod them out and resolder the tanks. Then pressure test them under water for leaks. Occasionally I would have a pinhole leak or two that no matter what you couldn't seal or didn't want to spend more time on it. The solution was to put a teaspoon of grey powder into the radiator. The Boss referred to it as Sure ****" claimed it fixed everything. I never had one come back. I would not recommend any of the liquid glop products. Keeping an eye on it for the time should keep you going without any consequence. As suggested, keep a gallon of water or antifreeze in the trunk.

Steve

 

Grey powder?...I also heard egg and pepper works...any truth to that?

 

Myth busters tested the egg fix, it actually worked. I don’t remember them testing the pepper trick.

I get it the egg in the radiator is suppose to be an emergency roadside fix. However, given the choice, buy a couple gallons of water, stop frequently to top off the radiator. Unless it’s a huge leak (by definition, not a pin hole!) you can limp a car several hundred miles this way. Obviously, if the radiator is hemorrhaging coolant, that’s not an option. But I’m guessing a egg won’t fix a leak that big either. Maybe several eggs, but then I’d be concerned about an omelette in my heater core.