Coolant expansion tank

[Habusailor]

On my stock 49 sedan with v8 flatly, if I put a coolant recovery tank I don't think it will bleed back coolant without some modifications to the overflow system. Once pressure goes down the spring on the cap will close and nothing can return. Is my logic correct or will it suck back in coolant?

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[40cpe]

When the coolant contracts it will pull air from the easiest place. If everything is tight in your system, it will pull it back through the overflow pipe drawing from the expansion tank.

[Habusailor]

Originally Posted by 40cpe

When the coolant contracts it will pull air from the easiest place. If everything is tight in your system, it will pull it back through the overflow pipe drawing from the expansion tank.

So it will work! Thanks for getting my head on straight


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[paul2748]

It seems to work in my 48 Ford (302) street rod and my 54 Ford with a 312.

[Tony, NY]

The proper radiator cap (vented I believe) allows coolant to be drawn back into the radiator.

[RobR'35]

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I've an open system on my '35.
I've made a pint size over flow jar.
Put a good quality hose from the overflow tube on the radiator into the top over the jar. Put the hose right to the bottom of the jar but cut the hose at an angle. This way it can breathe so to speak.I then put another hose out the top of the jar, only sticking into the cover of the jar an inch. I ran this hose to the back side of the front cross member of the frame as a vent.
It works great.
I'll get at times when hot out, maybe a half full jar. When the engine cools off it draws it back into the radiator.

[chap52]

Mine works great.. Tubing from radiator overflow goes into bottom of recovery tank. There is a built in overflow tube in the recovery tank should things get totally volcanic. Even in the Arizona summer my truck has not overheated. Chap

[RKS.PA]

Originally Posted by chap52

Mine works great.. Tubing from radiator overflow goes into bottom of recovery tank. There is a built in overflow tube in the recovery tank should things get totally volcanic. Even in the Arizona summer my truck has not overheated. Chap

Chap, if anyone can test an "overheating flathead and recovery tank", we can!!

Dick.

[blucar]

A coolant recovery system will not work on the older style of radiators which did not use a pressurized cap. There is no provision in the neck for the pressure part of the cap to seat to. I don't recall pressurized cooling systems being used until the early '50's.

[RobR'35]

I've the open system on my car Bill. Original radiator to the car. Large top tank.
I have it hooked up just as I explained in post #6.
It works perfectly.

[JimG]

I put one of those stainless steel overflow bottles on my 34 which has a pressurized system. It works great. No more puking out coolant and the system maintains the highest coolant level possible at all times, which should yield the lowest temperature.

[1931 flamingo]

I put a universal (NAPA) tank in my A because it was always throwing water, it sucks it back just fine. FWIW
Paul in CT

[Jack E/NJ]

My stock unpressurized early 38 has coolant recovery just like #6 & #10 above. A greased rubber cap gasket seals the top of the neck just fine. Jack E/NJ

[Merc Cruzer]

I find that if I overfill my radiator, it just throws out what it does't need and keeps the rest. No concern as long as it doesn't throw out so much that the top of the fins are exposed. I have to admit that a recovery system would be nice though.

[RKS.PA]

It's embarrassing when it "pukes" on your friend's driveway!!

[Jack E/NJ]

And no need to open cap anymore either. Check & add coolant via recovery jug. Jack E/NJ

[G.M.]

Originally Posted by 1931 flamingo

I put a universal (NAPA) tank in my A because it was always throwing water, it sucks it back just fine. FWIW
Paul in CT

Any plastic bottle will work as long as the overflow go's to the
bottom of the bottle with hose cut on an angle. Bottle has to be
vented. As the engine cool to 155 degrees a suction is created
in the engine and sucks the water back. A regular cap that seals
tight will work. A 4 lb pressure cap on radiators with the overflow
in the filler neck. Fill the water up into the filler neck. G.M.

[paul2748]

The chrome cylindrical tanks that are shown above work very well and look good. I have two of them in two different cars, but my cars are not all original.