radiator repair

[ozzmonaut]

I have a slow leak from the rad on my 48 special deluxe. I don't see any wet areas in the fin area, so right now my assumption is that it is in the lower body, probably on the very bottom, as it is not visibly leaking on the front or back of the lower body, but coolant is collecting in the channel below the radiator. It is possible that it is due to vibration, as the bolts were loose when I got the car. I will be removing it soon to check it out. For now, I just want to find out what the radiator is actually constructed of. Being as it is a non-pressurized system, I plan to solder the leak. But my choice of solder may depend on the metal type. Any experience or tips are welcome as well. 

 

Also, I am noticing quite a bit of water coming from the exhaust while idling, and more when revving. I know that moisture is common from exhaust pipes. But this seems a little excessive. The car runs great, so hopefully it is not indicative of a head leak. Anyone seen this before? Thanks

[Sniper]

If you are running coolant the exhaust will smell sweet if it's a leaky head gasket causing the water in the exhaust, that would be the smell of coolant burning.  Non catalytic converter cars will show water out the pipe until the entire exhaust system heats up.  Cool sections of the exhaust system condenses the water out of the exhaust.  As a side note, modern exhaust systems usually have small drain holes in the piping to drain and collected water out, to limit water collecting there and rusting it out.  Here's an example of one in a muffler

 

[Loren]

Coolant will also give you a white smoke in the exhaust. That's the glycol burning.

If the car has power brakes a white smoke cloud following you could also be a leaking Master Cylinder.

Brake fluid is made of glycol too.

You can get a quick test kit at NAPA which has a tool that fits in the radiator neck and holds a blue test fluid.

If you have a blown head gasket a one way valve allows gases from the radiator to bubble thru the fluid turning it golden when combustion gas is present.

 

[ozzmonaut]

I will check out that kit. Any ideas on soldering the leaky radiator?

[Sniper]

Only time I ever tried to solder a radiator is was a leaky seam, between the top tank and the core, I ended up chasing solder around the seam trying to seal it.  Ended up closing the gap with some epoxy.  It was a brass radiator, if yours is brass it can be soldered, clean it well first.  Solder doesn't stick to gunk and have flux handy.

Edited January 4, 2020 by Sniper

[Loren]

The Radiator Shop is an old car owner's best friend!

They can clean and repair a radiator with much less fuss than it's worth to DIY.

From cleaning out old gas tanks to putting more efficient thicker cores in your radiator, it's good to know the best radiator shop.

The Plymouths I've owned have all had honeycomb radiators, which seem to last forever.

I would try to have one repaired by experts before replacing with something else.

And if it was beyond repair, I'd find a used one before re-coring with the tube and fin type.

 

[kencombs]

15 hours ago, ozzmonaut said:

I have a slow leak from the rad on my 48 special deluxe. I don't see any wet areas in the fin area, so right now my assumption is that it is in the lower body, probably on the very bottom, as it is not visibly leaking on the front or back of the lower body, but coolant is collecting in the channel below the radiator. It is possible that it is due to vibration, as the bolts were loose when I got the car. I will be removing it soon to check it out. For now, I just want to find out what the radiator is actually constructed of. Being as it is a non-pressurized system, I plan to solder the leak. But my choice of solder may depend on the metal type. Any experience or tips are welcome as well. 

 

Also, I am noticing quite a bit of water coming from the exhaust while idling, and more when revving. I know that moisture is common from exhaust pipes. But this seems a little excessive. The car runs great, so hopefully it is not indicative of a head leak. Anyone seen this before? Thanks

It should be brass.  I've found that lead, highest % you can find works best.  Best cleaning method seems to be a little brass bristle  brush on a Dremel type tool followed by muriatic acid brushed on.  The dremel brush gets into fairly small areas, cleans well and it would be hard to damage anything with those little guys.  Clean and neutralize the acid well when done.

 

Really doubtful that a head leak severe enough to see water in the exhaust would not also cause a misfire. Cool weather, cold exhaust metal temps = lots of condensation.  About a gallon and a half of water is produced by burning one gallon of gasoline..  Along with 18 lbs of CO2.  Hard to believe that much is produced when you started with 1 gallon, about 6 lbs of gasoline!  But it does explain the abundance of water in the exhaust.

[Loren]

31 minutes ago, kencombs said:

It should be brass.  I've found that lead, highest % you can find works best.  Best cleaning method seems to be a little brass bristle  brush on a Dremel type tool followed by muriatic acid brushed on.  The dremel brush gets into fairly small areas, cleans well and it would be hard to damage anything with those little guys.  Clean and neutralize the acid well when done.

 

Really doubtful that a head leak severe enough to see water in the exhaust would not also cause a misfire. Cool weather, cold exhaust metal temps = lots of condensation.  About a gallon and a half of water is produced by burning one gallon of gasoline..  Along with 18 lbs of CO2.  Hard to believe that much is produced when you started with 1 gallon, about 6 lbs of gasoline!  But it does explain the abundance of water in the exhaust.

You are so right!

On an old car (especially air cooled) uses about 12 pounds of air to every pound of fuel. And as you say a surprising amount of water is produced. Water from the humidity of the air plus the chemical reaction from combustion. The optimal fuel air ratio for combustion (with cat converters) is about 13.5 to 1 which is on the lean side for performance and way too lean for air cooled engines (a rich mixture displaces air which results in a cooler running engine). I don't know about you but I can not visualize 12 pounds of air! Gasoline is a different matter, 6.3 pounds per gallon.

That fuel air ratio is pretty much the same at idle or highway speed.

Now diesel works very differently. On a diesel you throttle the fuel not the air.

A diesel at idle only needs enough fuel to tick the engine over. While a gasoline engine uses a 12 to 1 ratio at idle a diesel uses 144 to 1 ratio!

So what does this have to do with Plymouths and radiators? Not much, I just got carried away.

Although Chrysler experimented with diesel powered Plymouths and I know they had radiators.

You know a 4bt Cummins will fit in anything that had a flathead 6.

[ozzmonaut]

I think you are right on with the condensation. On the day that I really noticed it spewing water from the exhaust, it was very cold but also extremely humid, which does not happen often. My girlfriend even remarked that it was muggy outside, despite it being about 40F. The amount of water could not have been coolant without a misfire. I have been noticing a very slight misfire, but I think it is due to cap/rotor wear. I also need to rebush the distributor. 

 

I was pretty sure the radiator was brass. Unfortunately we don't have a radiator shop local anymore. I will check on some options for lead %. I always neutralize acid with baking soda dissolved in water. The leak is very small, and I think it should be an easy seal. If not, I would say epoxy will do just fine. Honestly, it almost isn't enough of a leak to worry about, but if I don't repair, it will get worse. Thanks for the help , everyone!

Edited January 5, 2020 by ozzmonaut

[Sam Buchanan]

On 1/3/2020 at 11:45 PM, ozzmonaut said:

I have a slow leak from the rad on my 48 special deluxe. I don't see any wet areas in the fin area, so right now my assumption is that it is in the lower body, probably on the very bottom, as it is not visibly leaking on the front or back of the lower body, but coolant is collecting in the channel below the radiator. It is possible that it is due to vibration, as the bolts were loose when I got the car. I will be removing it soon to check it out. For now, I just want to find out what the radiator is actually constructed of. Being as it is a non-pressurized system, I plan to solder the leak. But my choice of solder may depend on the metal type. Any experience or tips are welcome as well. 

 

Also, I am noticing quite a bit of water coming from the exhaust while idling, and more when revving. I know that moisture is common from exhaust pipes. But this seems a little excessive. The car runs great, so hopefully it is not indicative of a head leak. Anyone seen this before? Thanks

 

You are sure the drain cock is not leaking around the threads?

[ozzmonaut]

Not around the drain cock for sure. The car is a daily driver, so it might be a little while before I can pull the radiator. Lucky it is such a slow leak.

Edited January 6, 2020 by ozzmonaut