32 ford coupe - AFCO radiator - Overflow level?

[Simi Mike]

Hi all -
Had my intake manifold gaskets replaced, on my 32 ford coupe.
Now that the motor is cold, I checked the overflow tube, that is attached to my AFCO aluminum radiator. Its empty.
I'll add some radiator fluid in the overflow tube, but there are no markings for how much to put in. The chrome overflow tube is about 20 inches high. Should I fill it about 1/2 way, or less?
Thanks for your imput.
Mike Lanska
Simi Valley, California

[Dave Severson]

Is your overflow tank a tube about 18" long with 2 tubes on the bottom and a cap on top, or what do you have??

[jerry clayton]

It depends on what type radiator cap you have

[Simi Mike]

My chrome overflow tank, that is about 18" long, and about 2 1/2" around.
Yes, there is two tube inside. One - way down at the very bottow, and the
other is about 4-5 inches, from the top of the tank.
I know in my highlander, the overflow is a plastic 1/2 gal tank, and I usually
keep that alittle less than half way.
But, this tubular overflow, I'm not sure about the elevation the fluid should
be at - - when cold. I tried to get online, on the AFCO radiator website, but
it doesn't say anything about the overflow tank. I just thought, some of you
hot rodders might know what the elevation should be kept at. Thanks

[Dave Severson]

What is the water level at in the radiator??? With the setup you have, I like to make sure the radiator is at the proper level before putting anything in the overflow... You had the intake resealed so it was of course necessary to drain the coolant, now after driving it the cooling system has "burped" itself and hopefully got the air out of the system. With the engine cool, I'd suggest checking the fluid level in the radiator, and getting it to the proper level. Reason being if you overfill the radiator just a bit, the coolant tank will catch the overflow. Without knowing all the details of your cooling system, I'd think a couple inches of coolant in the overflow tank is plenty when everything is cold. The catch tank doesn't hold much, once the engine is at operating temperature if the overflow is empty again, then add a bit more. I prefer to do this and sneak up on the proper level rather then filling everything to the max and dumping a bunch of coolant on the ground......

[Simi Mike]

Thanks - that sound like a plan. I'll put a cup full of radiator fluid in the overflow, since its empty, and check it when the motor cools, after driving.
Thanks again

[jerry clayton]

IF you have a radiator pressure cap for a coolant recovery system the radiator will heat,expand,overflow excess into tank and suck it back into the radiator on cool down--thus keeping the radiator full to the brim----If you don't have a recovery system--when the coolant expands and overflows into the catch can-- it is out of the system forever---

[Dave Severson]

IF you have a radiator pressure cap for a coolant recovery system the radiator will heat,expand,overflow excess into tank and suck it back into the radiator on cool down--thus keeping the radiator full to the brim----If you don't have a recovery system--when the coolant expands and overflows into the catch can-- it is out of the system forever---

Thanks for adding that Jerry!!! My bad, I assumed it was the correct radiator cap--shouldn't do that, huh????

[Simi Mike]

Yes, both are under pressure. My tubular overflow, has a pressure cap on it. But it doesn't have anything in it ! I was going to put a cup full of radiator fluid in, and check it again, after it cools down - - - next time I go out. Its raining in So. Cal right now. Thanks again Dave and Jerry.

[34_40]

Yes, both are under pressure. My tubular overflow, has a pressure cap on it. But it doesn't have anything in it ! I was going to put a cup full of radiator fluid in, and check it again, after it cools down - - - next time I go out. Its raining in So. Cal right now. Thanks again Dave and Jerry.

Nope, that's what the second tube is for. Let's the pressure out! If it was a sealed container, nothing would be allowed in! The second tube should be within an inch or so of the top (generally..) Fluid any higher than that would come out and you'll know your system is overfull.

[rspears]

Yes, both are under pressure. My tubular overflow, has a pressure cap on it. But it doesn't have anything in it ! I was going to put a cup full of radiator fluid in, and check it again, after it cools down - - - next time I go out. Its raining in So. Cal right now. Thanks again Dave and Jerry.

I have the same overflow tank, but my overflow cap is not a pressure cap. Like Mike says, the vent lets any pressure out anyway, along with excess fluid. I also have a recovery pressure cap on the radiator, so it sucks back fluid to keep the system free of air. For what it's worth, I fill my radiator as much as possible, then fill the overflow to within about an inch of the overflow tube before going for a drive. After it cools down I check the overflow, and if there's fluid covering the inlet tube I fill it about 1/2 full. If it's empty I know that the radiator sucked in some air, so I fill it nearly to the top again before the next drive. Your cupful approach will work, but it may take you several trips of coming back to an empty tank to purge the air from your system.