New Radiator and Losing Coolant
 

First few voyages of a near complete restoration. First real drive the car - 28 Leatherback - overheated terribly. It was the original radiator and I had it checked originally and told it was good. I was spewing fluid after a short drive. Timing was great and so was carb air fuel mix. Checked an re-tightened the head and detected no leaks. So replace the radiator with one from Snyders. I believe both they and Brattons sell the same heavy duty one from a company in IL.

First run post new radiator was perfect. Ran nice and cool. Days later went out again and terrible overheating again. Come to find out I had very little radiator fluid in the radiator. Filled it and ran beautifully again. Went through everything with a fine tooth comb and no leaks anywhere. So where am I losing my coolant and how do I prevent it?? I've searched through the posts on here and have seen some things about new radiators and having to change the water pump impellers or adding a thermostat otherwise you can lose fluid through the overflow tube. Is this is what is happening to me?

As always, thanks in advance for the help. Advice from this forum has helped me figure out every problem I've faced so far!

Re: New Radiator and Losing Coolant
 

With the baffle in place you can not see the water level which would be just at or below it, when it finds it own level. If you over fill it will puke out till that level is reached. If you are not over filling, could be as you have suggested re the water pump or over heating could be; GVA or were you are setting the spark lever. Puking water out might not even be over heating, you would need to know what temperature it is really running at.

Re: New Radiator and Losing Coolant
 

During the motor rebuild which head gasket was used? The modern silicone impregnated head gaskets are reported to be problematic, and can blow as soon as within the 1st few hundred miles.


If any doubts, perform a Coolant Block Test, relatively inexpensive and very easy to do yourself, or take to a mechanic to have done. This test will tell you if you are getting exhaust into the coolant. The symptoms you are having could be this issue.


https://www.amazon.com/Block-Tester-...a-570352767565


Napa also has them, may have to be ordered.

Re: New Radiator and Losing Coolant
 

I too installed a new radiator and after maybe 2,000 miles it to leaked under the return pipe at the top. After conciderable thought I wondered if it was because the drive chain and engine moved forward just a little as the motor car accelerated and pushed on the rigid and stationary radiator. This I wondered was because I had installed float a motor which allowed for such small movement. I might add I am pleased with the new mounts.
I have now purchased a new hose which incorporates a concertina, yet to be installed.. Photo included. 18AUD.

Re: New Radiator and Losing Coolant
 

How much water did you lose and do you know what temp it was running at? If the rebuilder used the "modern head gasket" I'd say that's your problem. Sadly they turn to goo when exposed to antifreeze.

Re: New Radiator and Losing Coolant
 

I lost a little over 2 gallons in antifreeze. I ordered the block tester off Amazon as suggested and will see if it is a head gasket, etc. issue. Hoping I don't have to replace on a brand new rebuilt engine!

Re: New Radiator and Losing Coolant
 

Well, if you do, I'll be right there with you. Engine rebuilt last year, 5.5 head planed, torqued and retorqued, weeps around the head and looses antifreeze... I need to change the gasket before putting the car away for the winter. I'd hate for antifreeze to leak down into the cylinders and damage a brand new engine.

Re: New Radiator and Losing Coolant
 

First thing, don't buy the old wives tale about water pump pumping so fast that water piles up in the top tank before it can flow through the radiator. The water pump can only move water, not produce it. I would first make sure you don't have any leaks, antifreeze will seep and the leaks are not always noticeable if parked on gravel or dirt. Second, as others have mentioned, find a way to check actual coolant temps. Third, its simple enough to attach a hose onto the overflow tube and run it to a jug. That will give you an indication of where its going. The combustion gasses check in the radiator is simple and easy so that would also be a good check. Don't just accept some overheating! I've heard it a hundred times "Oh that's just how a Model A is, you can't push them too hard when going up hill". Baloney, if cooling system is in order they cool very well. However, this is all contingent on running the correct advance. Any Model A will overheat if you run them too retarded, and will be really tough on bearings if too advanced.

Re: New Radiator and Losing Coolant
 

Loosing two gallons of coolant is alarming.
Are you absolutely sure your timing is correct? Before setting timing did you check that the advancement arm that protrudes through the distributor body travels fully from one side of the opening to the other side when the spark advance lever is moved fully up and then down?

When you set the timing did you have the spark lever all the way up?

Are you using the NuRex wrench to set the timing. If not maybe you should give one a try. Simple to use and gets the timing pretty darn close.

You (us too) need to know for sure what the coolant temperature is. Get a cheap dial or digital meat thermometer and test the coolant temperature directly and check it often. This is the only way you will know for sure what is going on with the coolant temperature.

Re: New Radiator and Losing Coolant
 

Re"First thing, don't buy the old wives tale about water pump pumping so fast that water piles up in the top tank before it can flow through the radiator."


One of the reason they sell water pump impellers with clipped ears is because it has been a reported issue of pushing water too fast thru the radiator and forcing it out the overflow. Search this board and read the number of times that this has been talked about.

You can only check with a meat thermometer if the water is over the baffle which it should not be anyway. I would suggest one of the hand held instant read types, the aim and press the button type.

Re: New Radiator and Losing Coolant
 

With that said,,, does the moto meter use the steam from the coolant or ambient heat in the radiator? Sloshing water up on it? Last seems silly but I have no idea.

Re: New Radiator and Losing Coolant
 

The motometer does read the steam or air temp in the radiator. I think it has been said here that the lag time can be as much as 5 minutes between the actual coolant temp and the temp reported on the meter. I do tend to notice mine heats up after I finish climbing a hill.



Back when I had the old engine with a very leaky head gasket I would lose about a gallon of water and the meter would spike quickly.

Re: New Radiator and Losing Coolant
 

I have checked the advance arm movement in the distributor body and it is good. I also did use the NeRex wrench to set the timing. Like you said it gets it pretty close and pretty easily. Will pick up a digital meat thermometer and check on the coolant temp. What should it be roughly?

Re: New Radiator and Losing Coolant
 

When it's all warmed up it should run somewhere between 160-190.

Re: New Radiator and Losing Coolant
 

Running temp is dependent on cooling system condition, and outside temp.


Have a new Bergs radiator, motor rebuilt last winter so no rust in head/block, running antifreeze. Spring and fall in WI it is lucky to get to 120 degrees, so I run a 160 degree thermostat with bypass holes drilled in it. Summer up into low 90s it runs about 170 - 180 with the thermostat.

Re: New Radiator and Losing Coolant
 

I agree with 30 Closed Cab post #3. It is entirely possible that you will not see any coolant leaks around the engine or coolant in the engine oil. You certainly could have a blown head gasket allowing compression leakage into the cooling system. The compression leak creates a pressurized cooling system forcing the coolant out of the overflow pipe when the engine is running. I would buy the kit and check to see if any exhaust gases are in your coolant. This certainly could be the answer to your problem.

Re: New Radiator and Losing Coolant
 

As an FYI, the reason I did not additionally suggest a compression/leakdown testing is from his info seems his motor was recently rebuilt. Readings could be misleading if motor is not yet broke in.

Re: New Radiator and Losing Coolant
 

rundmt123 - Any updates?

Re: New Radiator and Losing Coolant
 

When you go to HF to get your Battery Tester, buy one of their Laser Thermometers
https://www.harborfreight.com/121-In...ter-63985.html

just a thought. 2 Gallons is way to much to lose.

Re: New Radiator and Losing Coolant
 

holdover - Does that one work with the motor running?


I have one that I can not use within about 5 feet of a running Model A motor. Electrical/ignition noise causes it to go haywire.