Coolant Information

dekberg

dekberg

Junior Member
Good evening folks. I started removing parts from the engine compartment since I got my old boy on tires and rolling. Everything going smooth so far but got a radiator question. The car hasn't ran for more than a few seconds at a time in 30 years but it was full of coolant still. I think it is a pretty good sign that a) it was still full and b) there was no rust, dirt, or crud that came out while draining. Am I correct with my assumption? I still plan on flushing the radiator and I know it is a good idea to take it and test it while it's out but do I just use the good old green stuff when I refill? It's times like these I really miss my dad to answer my dumb questions.Thanks for your advice.
 
You are correct, the cooling system is probably intact.

The radiator is likely partly blocked. Get it rodded out by a good radiator shop. A good radiator shop will be in the old part of town, has been in business for a long time (like 50 years) and they will recognize that Model A radiator as soon as you walk in the door with it.

Water with anti-rust additive is best in the summer. Change to the green stuff in the fall before it freezes. Run it all winter. Switch back to water in the spring.

There are no dumb questions. Ask away.
 
I would take the car for a good drive before taking anything apart.
The car might need nothing more than a tank of good gas and a driver.

Lube all the moving parts, grease or oil. I use antifreeze year round.
 
I prefer to run antifreeze all year round.
your cooling system seems to have been preserved for 30 years with it why change
Your radiator maybe fine also.
I would do a drain and fill, drive it and then test things such as the rad temp using a ray gun or a thermometer. Improper timing or misuse of the spark advance will make the car run hot also so don't jump to conclusions.
If it isn't broke don't fix it
 
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My roadster, which had not been run much, but restored in the last 20 years and which had an original round tube radiator, didn't have any overheating problems when I bought it. I did not drain the cooling system, which I probably should have done. It started overheating and I took the radiator to a shop. The radiator was plugged and too fragile to rod out, unfortunately. My point is that all seemed good when I bought it and then problems started, so I think you won't know until you try. At least you drained the radiator first. It seemed like my driving the car a lot stirred up a lot of junk in the cooling system, which ended up in the radiator.
 
Thanks for all the information. As a follow up the radiator has been flushed and checked and is in great shape. Now the crack in the frame right under the radiator is a whole different beast.
 
I do not run a thermostat and have no issues. However, if you do make sure to drill adequately sized bypass holes. Myself I would use 1/4" holes, maybe three of them. I don't drive my A in the winter because of the amount of salt on our roads, and in the summer months the engine heats up quickly and has not ever boiled. The biggest reason I see for a thermostat is to raise the pressure (actually reduces vacuum, which is negative pressure) slightly in the engine, therefore raising the boiling point a bit around the cylinders. If the thermostat has NO bypass, the water pump is going to be cavitating and that is a problem. Flash boiling on a cavitating pump is going to cause a rapid expansion of coolant, forcing coolant back into the radiator in big "burps" which will spurt out your overflow tube. Even with the thermostat completely sealed it will burp backwards through the bottom radiator hose. Hot spots in the engine will do the same thing. Coolant flashing to steam is a HUGE volume increase with LOTS of power behind it. Trouble with a capital T.
 
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