I've recently started using my /6 Dart as my daily transportation. I'm driving around 50miles per day.

A few days ago I was checking fluids and when I pulled the radiator cap off, I was looking at the tops of the tubes in the radiator. I started adding antifreeze and it took about a quart to fill it back to normal.

A couple of days later I thought the temp gauge was running a little high. Not over heated just a little higher than normal. After it cooled off, I checked the radiator, and again I was looking at the tops of the tube,, with no antifreeze visible. I started adding some and it took about a quart.

This was weird cause I haven't seen any wet spots under the car. Finally tonight, the car was warmed up, then parked for 1/2hr. then I drove it home a couple of blocks, got out and noticed a trail of antifreeze leading into the driveway. Sure enough it was spitting up a little out of the over flow tube.

What causes this,,, Is my radiator cap bad, or do I need a cap thats rated for higher pressure ? It has a 16lb cap on it right now.

Thanks

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

In regard to that thread...

I don't think I agree about the "free hanging" valve being used on "all mopars from the dawn of time." I still have the factory cap from my '73 Satellite- it aint free hanging. I don't ever remember even SEEING a free-hanging valve until about 10-15 years ago, when I got one by mistake and it instantly resulted in the car puking coolant every time I shut it down hot!

My advice and experience is to avoid the free-hanging type like the PLAGUE unless you have a coolant-recovery system. A non-recovery system will simply consume far too much coolant with the free-hanging type- even if it doesn't "puke" it out like my cars (all 3 of them- I tried the hanging-valve cap on them all!), the hanging valve loses more through evaporation because it vents the humid air out of the system EVERY time the engine warms up. The spring-valve type doesn't do this, so the water vapor is much better retained in the system.

Maybe they type of cap that came from the factory in the olden days was a regional thing- I can tell you for certain that even in a 100% healthy cooling system, the hanging-valve type don't work well in Central Texas in summer.

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Actually what SuperScamp describes is normal for his type of cooling system. The water should just be above the radiator fins. When the water heats up, it needs to go somewhere, that is what the upper tank is for. If you fill the radiator to full, the the water will exit thru the overflow hose.

This is normal operating procedure.

More modern cooling systems use an overflow tank to catch the overflow and reintroduce that water back into the cooling system as the entire system cools off.

Just to clarify, when I stated I could see the tops of the tubes, what I meant was that the upper tank was completely empty,,, I couldn't see any antifreeze at all.
Yes, its possible that I was over filling a little but not clear to the top or anything, and I dont think its normal for it to puke so much that it completely empties the top tank.

But anyway, I picked up a coolant recovery tank at Carquest auto parts this afternoon and installed it as soon as I got home. It was like $11.00
Its not a really big tank but I think it will be good enough. I dont think the car was loosing a quart every time I drove it. Just think that it added up to that amount after 2 to 3 days. Also I checked my cap and I already had the correct one for a coolant recovery system. (meaning the cap with two rubber seals).
Heres a pic of the installed tank,, Had to remove one of my horns, but i'll find a new location for it tomorrow.
Thanks for the info everyone.

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