VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 radiator coolant loss

Hello Chevrolet experts. Just had the original radiator repaired for my 1950 Styleline Deluxe Town Sedan. ( 2 times actually....same shop....1st time small crack in lower tank, 2nd time leak in the core.) The car is 90% original, has 23,000 miles. It is all back together now, seemed to run & drive perfectly fine yesterday and no leaks. This morning, took cap off , looked into radiator, and it was obvious there was a small amount of coolant loss overnight. I did not measure, but the level in tank was down perhaps 1/2 inch. Maybe a cupful or more ? ( I did not add any coolant as of this writing ) Where did it go ? Again, I looked very carefully and hopefully thoroughly and there seem to be no leaks anywhere. I know antique cars are quirky and cantankerous sometimes, but is this " normal" ? How much loss can a person expect? Seems like a lot to me. What am I not understanding/doing wrong ? Suggestions, hints/ ideas ? Thank you.

More than likely there was some air in the cooling system that did not come out until later. It is a common event when refilling the cooling system. I would add a little coolant and then check it again later. Once the air is gone then the level should stay constant. That is unless the level is too high and some comes out the overflow when at operating temperature.

Ok, that makes sense. I added some this morning and measured, it was 1 & 1/4 " below the bottom level of the filler tube. I will check it Friday sometime and if there is no loss, probably I am back on track then.

Ok experts....the coolant loss saga continues. Drove 70 miles yesterday to a car show, parked, open my hood for judging as usual routine. There was nothing leaking on the ground. ( I have attached a small plastic tube to the metal overflow tube on radiator, and routed it down between frame cross members..it would be obvious if any leakage )

Before leaving, I had to add probably 3 cups of anti freeze to radiator.

It is NOT leaking from the following : Radiator, heater core, heater hoses, upper or lower radiator hose, thermostat housing pieces, crack in engine block, freeze plugs.

On the right side of engine ( pass. side ) towards the very front of the block, there is a horizontal " lip " near the fuel pump. This was wet, almost al the way back to the distributor, also some parts of the suspension control arms on that side. So, it is coming from somewhere !!!!

If the block ( head ) gasket is leaking, wouldn't that mean some would be leaking down into the oil ? I am thinking my oil would have some sign there is coolant in it . ( is that easy or hard to detect ) The oil seems to be perfectly normal.

If the water pump is leaking, wouldn't that be really obvious ? I am really confused. This has me stumped.There is leakage..but where ??????

Thanks all in advance.

The water pump has a drain hole on the bottom check there for leak
Al

The coolant expands with heat. First check it before you start the cold engine......then check it the next time under the same condition.
The coolant height will raise about 3 to 4 inches when hot.
For mine I keep it just over the core tubes when cold. Never bother to check it when hot.
The 1950 216 engine cars did not come with a pressure cap. Try a 4 pound cap and see what happens.
My '50 developed a leak in the heater core which I discoverd by accident.

Ok..thx Al....will check that...I did read about that and saw the diagram.

Chevygene...thx for that advice.....I know it expands...maybe I am filling it too full and it is coming out the overflow tube as I am driving, and as soon as stopped, it just quits coming out ????

I keep the coolant level a couple inches below the top of filler tube. Too much ? Wanted to make sure I had enough coolant in it.

As I said, it seemed to lose 3 cups of fluid, which to me that seems like a LOT.

What is the proper level of coolant to keep in the system , meaning when you open the cap and look down into the radiator, what are you supposed to see?

Also...just had radiator repaired 2 times....2 leaks found, 1 in core, 1 in lower tank. It is NOT the radiator this time.

Tomorrow I am going to clean all the drips and spots and leakage that I can see, start the car, let it get to operating temperature and shine a good light on things and see if I can locate the source. Stay tuned......keep that advice coming though. Appreciate you all !!

Everyone who advised that the level in the top tank should not be over half full is right on.

I would suspect that you try to keep it too full.

If that is not the source of the problem then consider the following:

a. Water pump. When they start to leak, it is not a lot at first. Gets worse as it is ignored.

b. Head gasket leaking compression into the water jackets.

c. Cracked head. About the same symptom as head gasket. (Usually, between spark plug holes.)

d. Cracked block. Ditto.

e. Radiator is stopped up to the point it will not take the flow coming from the water pump. Accordingly, it raises it up until some will come out the overflow tube.

f. Ethanol. Well, it gets blamed for all other phantom stuff.

Note: It is easy to check for compression leaks:

a. take the thermostat housing off and the thermostat out. Replace housing.

b. fill up until the coolant (water) is level with top of housing.

c. Trip the fan belt.

d. Crank the engine and look for bubbles or worse. (Don't overheat the engine. You will notice any bubbles or a gush of water almost immediately.

You can use a mirror to look at the hole below the water pump shaft to see if it is leaking.

Good luck,

Charlie

Ahhhhhhhhhhh !!!!! Thanks ! Yes, I believe I was keeping it too full. I checked all hose clamps, connections, bolts, etc. etc. yesterday. Started up car ran to operating temperature and beyond ( 20 minutes ) Ran like a top as usual. When I shut it down, carefully removed the radiator cap...the fluid level had risen 1 inch. I figured out this was about 42 inches cubed , or close to 1/6 of a gallon increase ( based on measurements I took of the radiator ) . This is probably about 3 cups, which is what I seemed to add the last time. There were no leaks, and nothing was coming out the overflow tube. Since I was keeping it pretty full, I suspect as I was tooling down the road, it was all coming out the overflow tube and just dripping out all over the place, and , once parked, it just quit flowing out.

I will keep an eye out for the other symptoms and fix these as need be, but I suspect it was me being overzealous on filling.

Thanks Charlie and all for the great advice. It is great knowing there are experts out there we can rely on to help us keep our beloved Chevrolets running and operating !!

I

Okay,
Just so I am on the same page. 1941 Master Deluxe, 216, all original. When I look inside the radiator before I head out for a show or parade, should I be able to see coolant? The engine is stone cold.
Gus...

Yes. Water will expand and rise in the top tank as it heats up. If there is too much it will vent out the overflow pipe until it reaches a stable level. The stable level is about half a top tank full to just above the flues.

You do have check it once in a while. If cold and below the flues you will not know how much is in there. Keep it topped off, i.e. about half the tank.

This is where t he overflow tank comes in handy. It will likely hold the excess when hot and not need topping off near as often - or that's the way it's supposed to work. I have never run one on my old cars that came without a pressure cap.

Check with others about how well they work.

Best,
Charlie