Is it normal for a car with no overflow to dump a bit of antifreeze after a day

driving in high heat 90 Deg ? Been 40 years since I've driven something with no coolant recovery , might have been 1/4-1/2 a quart r less .

Is it dumping or evaporating, Mine will get up there 210 or so but never see it on the ground or undercarrage, and I`ll top it off once or twice a year. So I guess it`s evaporating? I add about what you describe.

No it was on the ground , maybe just a bit of antifreeze mixed with the heavy rain and it looks worse , Ill check level next day or so . Hope it not a problem

I have heard of this happening. I wouldn't worry about the car from a mechanical standpoint.

blackbomber said:

I have heard of this happening. I wouldn't worry about the car from a mechanical standpoint.

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Thanks been a while for me with an older car , really nervous , will get an overflow tank from somewhere just so if I do se anti freeze on the ground I'll know it's trouble . This way I worry and it MIGHT be nothing .

If your radiator was too full, it would be normal for it to puke out a little after it was driven far or long enough to get to operating temperature.
C

I've had a couple cars do this from time to time. usually after running in high temps, it would dump a little after sitting. I had a 62 Impala that would do this often. MMG

It is normal if you fill the radiator up all the way, antifreeze won't boil at 212 like water but it does expand when it gets hot and has to go somewhere.

Thats why they put in overflow tanks. My 67 used to do it if I parked facing down hill.

Thanks all , looks like overflow tank from a 72-74 will be going in ,end of prob

I have a rubber hose from my radiator that will leak out a little coolant if I fill the radiator too high. After driving in the hot weather I always check my radiator levels as general pratice to see if any of the coolant has evaporated, sometimes I need to add a little water, usually less than a 20 oz bottle to top it off again. My car runs cool about 195 degrees, I got a radiator cap that has a thermostat built into the cap so I can constantly monitor the temperature level.

If you add a coolant recovery tank make sure you use a radiator cap that's designed for use with a tank. They have a rubber gasket under the cap as well as one where they seal in the radiator neck. I don't know, maybe all the new caps are like this now?

'64 Cuda said:

If you add a coolant recovery tank make sure you use a radiator cap that's desined for use with a tank. They have a rubber gasket under the cap as well as one where they seal in the radiator neck. I don't know, maybe all the new caps are like this now?

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Thanks , that's a good point . Do I need a special cap if I decide to use the coolant recovery tank ? More to research , thanks .

Check your radiator cap. Spring may be getting weak

The old school way is to run the overflow hose into a bottle wedged down along the radiator on the hose side. Keep a little fluid in the bottle so the radiator can syphon up some juice if needed and keep critters out, but leave most of the bottle empty. Every Mopar I have ever owned has found it's own fluid level in the radiator, mostly about an inch or so above the cooling tubes. If I fill any of my cars up all the way, it'll surely fill the overflow bottle until it gets down to it's "happy" level. I use a 22oz. pop bottle and drill a hole in the cap the size of the overflow hose. Not the prettiest, but I've done this for years and see no reason to change now!!!LOL!!! Good luck with your project, Geof

Right not my car is missing the hood. As I drove it I would notice my windshield getting spots of water on it. So like cosgig said. I have a gatoraid bottle with the hose going to it to catch any small amount of water\antifreeze.

jerry6 said:

Thanks been a while for me with an older car , really nervous , will get an overflow tank from somewhere just so if I do se anti freeze on the ground I'll know it's trouble . This way I worry and it MIGHT be nothing .

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Just part of the charm, in my opinion. As a dog lover, I would want to keep that crap off the ground, though. My '73 had a factory overflow added before I bought it.

The upchuck will stop happening once the coolant volume is no longer excessive. Filling the radiator right up to the filler neck ring when cold means there's nowhere for the fluid to go once it's hot — except onto the ground. If you don't want to add a tank — universal add-on tanks are readily available — then let the fluid find its level and don't add coolant just because the level is an inch or so below the filler neck ring when cold.

Radiator caps are more complicated than they might seem. A cap for a recovery system has two rubber seals: One on the face of the main valve, which seals against the lower flange ring of the radiator neck, and another larger one just under the cap's underside, which seals against the upper flange ring of the radiator neck. The upper ring's seal against the upper flange means that when the system cools down and coolant volume in the radiator decreases, the resultant suction is channeled via the open centre valve through the overflow tube, which draws coolant from the reserve tank back into the radiator.

A cap intended for a non-recovery system has only the lower seal, no upper seal. When the system cools and volume decreases, the centre valve opens and admits air to the system.

There's no problem using a dual-seal cap without a recovery tank, but a recovery tank won't be of any use if your radiator cap hasn't got the upper ring in addition to the lower one.

There are two kinds of centre valve. Chrysler's rad caps had the free-hanging valve clear on up into the early '90s, at which point the spring-loaded type began appearing on Mopars.

The difference between free-hanging and spring-loaded centre valve isn't whether the cooling system has a recovery tank or not. Rather, it's to do with the design of the cooling system: Partial-pressure (free-hanging valve) vs. full-pressure (spring-loaded valve).



In a partial-pressure system, the cooling system does not become pressurised until the system becomes sufficiently hot that the coolant and/or steam wants to rush out of the filler neck. At that point, the coolant trying to flow out of the radiator closes the cap's centre valve, and system pressure builds. It continues to do so until the cap's pressure rating is reached, at which point the cap's main valvespring is compressed and coolant flows out of the filler neck via the overflow tube.

A full-pressure system begins building pressure as soon as the coolant begins to heat up, and retains it long after coolant outflow would cease to push closed a free-hanging centre valve. This can offer increased protection against localised boiling in the system, which can be necessary in engines prone to such. However, the cost is greatly increased physical stress on the entire cooling system -- hose junctions, seals, solder joints in the radiator and heater core, etc.

So, leaving aside the pressure rating differences, and the physical differences (shape, size, length of centre stem, etc.) there are four different types of cap:

With lower ring only, with free-hanging centre valve (Partial-pressure, open system)

With lower and upper ring, with free-hanging centre valve (Partial-pressure, coolant recovery system)

With lower ring only, with spring-loaded centre valve (Full-pressure, open system)

With lower and upper ring, with spring-loaded centre valve (Full-pressure, coolant recovery system).

I run my cooling systems unpressurised (a 4-pound cap) in conjunction with waterless coolant which is costly but good (my comments here, here, and here for discussion and here for the company's website. Not only is it more effective at extracting heat from engine metal because there's no localised boiling, but the lack of system pressure means much less stress on every gasket, seal, hose, the radiator, the heater core, the heater valve, etc.

As usual great interesting info Slantsixdan ! Not sold on the evans fluid , your last post stating might not work with some older rads , will stick with 50/50 ,and coolant recov tank and cap from a 1974 Dart , don't think it is a pressurized system . Not 10% sure though .Oh and not to forget the distilled water , have always used that and in 40 years have never had a rad failure , and I put over 450,000 km on my cars before selling them . Of course I change all fluids every 2 years , brakes steering , rad and diff , Trans and oil more often . With the right maintenance cars last .
Thanks again for the informative post !

found the problem , cap was not good , gave up at 10lbs pressure . Replaced it and no more dumped fluid .

great info /6 dan!!!!!!