Radiator leaking
 

Hello, I’m new to Model A owning and recently bought a 1931 Tudor. Was doing fine until the other day after a drive on a hot day had the temp gauge go way up. No signs of overheating though. Parked it and then later added coolant thinking it was low. Next morning found a nice puddle of coolant on garage floor. You can see the fluid coming out on the fins at the very top floor of radiator on passenger side. Does have some rusty color to it also. Thoughts? Plugged? Rusted through? Previous owner said it was put in new six years ago. Tim

Re: Radiator leaking
 

My option would be to pull core out and repair it, or have it repaired by a radiator shop. I suggest not pouring in any stop leak just yet. Without seeing it myself, sounds like an easy fix where the vertical tube is soldered to the top tank and there may be where your crack is. There are other ways to pinpoint where the leak is. Over-filling, bad cap gasket, etc.. is ruled out since you say you can see where it's leaking. To solder it up yourself, you must know how to solder a radiator core. Shiny, clean is mandatory at the point of repair.

Re: Radiator leaking
 

I would take it to a shop and have it cleaned and repaired.

Re: Radiator leaking
 

Thanks for the comments regarding the leak. I’m hoping for an easy fix also. Save $$$. You mentioned a bad cap gasket. What symptoms would that show? It hasn’t leaked out the cap.

Re: Radiator leaking
 

Coolant on the windshield and hood is one symptom.

Re: Radiator leaking
 

Oh no. Thankfully don’t have that problem.

Re: Radiator leaking
 

When you bring it into a radiator shop make sure to tell them it is unpressurized. Model A radiators can be ruined if much pressure is used in testing.
Another thing, are you sure its leaking? Model As should be filled just to cover the tubes, as they don't have an overflow reservoir. When filling, if you splash a bit it can hang for a long time, won't evaporate like water. (if you're using antifreeze mix) Also, if its rusty, flush and change. When mixing coolant and water to put back in, use either distilled or RO (reverse osmosis) water, not tap water. Check the overflow tube, make sure it runs down the side and is soldered well.

Re: Radiator leaking
 

I'm with Eagle on as you need to make sure that it is actually leaking or not.

You just might be doing what many (most) folks new to Model A's do is to overfill the radiator.

There is a lot of flow coming from the water pump into the top of the radiator when running at higher speeds. The coolant expands as it heats up and that combined with a high coolant level, the increase in flow and possibly the baffle being damaged, deteriorated or missing will cause water to push out of the overflow tube and also seek it way past a faulty or loose radiator cap gasket.

Drive your car and let it push the excess coolant out until it finds the level it is comfortable with. Just keep checking it to make sure that it stays above top of the tubes in the radiator. As long as it stays above the tubes you are fine as far as the coolant level is concerned.

You say that it got hot but not to the point of overheating. Do you know for sure what the temperature was? Do you have a gauge or a motor meter on the radiator cap? The motor meters get you in the general area on temp but by no means are spot on accurate.
I use a cheap dial meat thermometer that I place in the neck of the radiator directly into the coolant. You can open up the radiator at any time since it is not pressurized and check the temperature. You really need to know what the temperature is for sure if you suspect overheating. Frankly I think it it a good idea to check the temperature of any "new" A for a while to get a good feel for how it is behaving temperature wise.

If you do have a small leak in a seam or someplace that is easy to get to there is a simple fix that while may not be a permanent fix is a pretty darn long lasting fix. It also save's $$'s.

Cut a piece of cotton tee shirt type cloth just a bit bigger than the crack and saturate it with silicone gasket sealant and apply it over the failed area. Of course clean the area very well first. Using black cloth and black silicone will help keep it from being too noticeable.

I've done this type of repair to many different things and it works well. Did this to the radiator on my AA on a small leak in the area you are looking at just about 10 years ago and it is still fine.

Welcome to the hobby. Fun stuff this is.

Re: Radiator leaking
 

Try stop leak first. Just may fix it until you do pull the core.

Re: Radiator leaking
 

Thanks everyone for all the suggestions. Radiator itself leaked for days. Got it to stop today after using BarÂ’s Leaks Stop Leak. Recommended by a well known Model A gentleman in the Valley here. I know IÂ’ve read opinions on stop leak items is 50/50 but it worked for now. Saved $$. Also got a good reference for a good Model A mechanic in case I need to have the radiator fixed. Helps to network!!

Re: Radiator leaking
 

Try just plain water, not a coolant. Water cools better. High temps can cause water to overflow and present as a leak. Model A radiators like to find their own fill level too. Also, make sure you are timed properly and driving the car with the spark lever about half way downmto avoid overheating. Lots of things can look like leaks in hot weather when sometimes it’s just water overflowing out the overflow tube.

Radiator problems can take the fun out of owning and driving a Model A. I have tried all kinds of shade tree tricks in fifty years of playing with these cars. The best fix I have found is new reproduction radiators. Yes, they are expensive, but to me, for reliability and peace of mind they are worth it.

Re: Radiator leaking
 

Crosscut/Dave: interesting tip on the radiator patch. I have an old radiator on my engine test stand that’s got a small intermittent leak. I just might try your trick.

Re: Radiator leaking
 

Let me know how it works out for you.

Re: Radiator leaking
 

Well whats the latest results? We can't wait any longer!

Re: Radiator leaking
 

Just had my radiator pulled out and sent to a shop to be repaired. The top hose neck was leaking pretty bad from a poor repair job from previous owner. Was $90 to be properly fixed, cleaned up and made to look like new.

Perfect time to install new hoses and clamps. Dang clamps are $$$ but are pretty.

Re: Radiator leaking
 

Common place to fail. With a stiff upper hose and a little engine movement, that area gets loaded pretty good and fatigues. We really need a flexible upper hose.

Re: Radiator leaking
 

I sent you a PM.


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Re: Radiator leaking
 

Hey everyone. Thanks for all the great advice. Here’s an update on the radiator leak. The stop leak worked for about two weeks but unfortunately after the Sunday Drive at Dawn coolant decided to start oozing out the front of the radiator back up in the front passenger side corner. ��. Looks like it may take a bit of soldering to stop it. Bummer.

Re: Radiator leaking
 

If you take the radiator to the shop for repair, be sure to tell the shop not to mess with the top row of fins or you may see the repair below the radiator shell. I had a radiator repaired years ago and the shop bent up the fins at the top of the core. When I put the shell back on, it didn't go low enough to hide the repair. As far as I was concerned, the cored was ruined, the front of the car looked awful. Ed

Re: Radiator leaking
 

Good to know. Thanks.