The Stovebolt Site Forums The Shop Area Engine Shop Coolant reservoir

I own what I think is a stock unmolested 1952 3100. As far as the cooling system, am I understanding correctly that these trucks did not have a coolant overflow reservoir new? All I have is the overflow line that runs down the side of the radiator. With everything available today, what is the best antifreeze and mixture to use? I’m in NJ. Thanks in advance!

Originally, no coolant recovery system. A completely filled properly operating cooling system would blow out some coolant as it expanded when the engine warmed up and would be down an inch or so when it cooled down. If you are not worried about originality, a recovery system is a good idea.

A recovery tank should be as close as possible to the level of the overflow nipple on the radiator filler as possible. I've seen the tank bracketed to one of the brace rods from the firewall to the radiator support. The less the suction in the radiator has to lift the coolant to refill the tank, the better. another good spot would be on the firewall at approximately the level of the top tank of the radiator.
Jerry

You asked what coolant to use. Stick with the standard green ethylene glycol 50/50 mix with water.

If you don't want to install an overflow recovery tank, fill the radiator so that it covers the tops of the tubs - about 1 1/2" down from the tom of the tank. Don't worry if you over-fill it. When it heats up it will discharge the excess coolant out of the overflow tube and self-fill to its maximum when it cools down.

There was a coolant recovery tank (overflow/expansion/whatever) available as a dealer installed option/accessory. I found mine on a truck show show swap meet table a few years ago (NOS). It has since had much of its writing/instructions ablated. If you have a factory Harrison heater installed, it won't go in the intended spot.

Thanks!

Thanks for the info

Ol' Roy had this reservoir on it when it came to me. I decided to leave it in place even though i prefer a slightly different design.

It's in the same location as John's and work's perfectly.

I've installed coolant reservoir recovery tanks on several antique vehicles and always use this particular one.

Dorman #603-001

I like it better than the one that's on the truck because it has two mounting ears instead of just one. It also has the tube in the bottom instead of a tube attached to the cap making it easier to fill.

They're available anywhere but Rock Auto has the best price last time I checked ($8 instead of $23). That's it in the last photo on my '66 Toronado.

Dorman 54002 twice as big. Comes with cage etc.....

Back in the day, wasn't there a way to use a coke bottle for this? Or did I just see somebody's homemade rig using a coke bottle?

You probably saw a homemade one. Any type of container would work, although a Coke bottle would be almost pointless due to the limited amount of coolant it could hold.

The recovery tube would have to be inserted so that the end of the tube is all the way at the bottom of the bottle.

Millertyme - Welcome to Stovebolt! Looks like you've been lurking for a bit and glad to see you've joined the conversations here.

If your interested in more information on coolant recovery stuff others have used, you should check out these older threads on the topic. Unfortunately some of the old posted picture links are broken, but there are still several good ones and great info to consider when you decide on what you'd like to do with your truck.

2011 Coolant overflow tank thread

March 2026 Overflow tank thread

There are other threads if you use the Search Feature to help find such things in our archives.

Come back and let us know what you decided to use. Pictures would be as always much appreciated.

The first one I fabricated used a 1 quart brake fluid can, with a piece of copper tubing soldered into the screw-top lid. Recovery tanks also need an atmospheric vent to account for fluctuating liquid levels, and the standpipe that's connected to the radiator vent tube needs to extend almost to the bottom of the container, submerged in a little bit of liquid so it can siphon coolant back into the radiator as it cools off.
Jerry

If you're interested in keeping your truck looking old school, several vendors offer reproductions of the original accessory coolant recovery unit mentioned by John Milliman above.

Here's one offered by Classic Parts if your so inclined.

Does the top come off? If not, the problem with the original style is that you can't tell how much, if any, coolant is in the reservoir.

which is a good thing to know.

Setup on my 58 truck, Clear tubing top

When adding the coolant tank do you recommend a 4 lb cap to the radiator? Or a double seal type cap to help rerun fluid back to radiator while engine or is it more in the placement of height of overflow tank?

Thanks Glen

If you're using a stock radiator, you can only use a 4 lb cap. Otherwise you risk rupturing the tubes.

I use a 4 lb radiator cap on my system. Just make sure that it has the poppet valve that modern radiator caps have so that fluid can travel in both directions.

Even if you have 216 with a zero pressure cap?

Yes. My car has a stock 216 engine and I use a 4 lb pressure cap

Not sure if this is a pressure or non pressure cap but wouldn’t hurt to replace it when I add the tank.

See that little disc at the bottom of the cap with this small rubber gasket? That's the poppet valve. That is a modern reservoir style cap. It will work.

And you'll know right away whether it's working or not. Install it with the radiator filled to the top. After you drive the truck around and the engine heats up you'll notice the reservoir tank has more coolant in it.

After the engine cools down in several hours, the reservoir tank will go back to normal. If it doesn't, well then that little caps not working

Great. Thanks for explaining