Coolant spewing from my overflow hose

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mghikas

mghikas

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hey guys,
I have a new 3 core radiator on my 72 Demon.
Temp holds well when I’m driving about 180-190, as soon as I sit in traffic or turn my car off I get coolant coming out of my overflow hose.
I don’t have an overflow bottle.
What psi cap should I be running?
What do you guys think could be the problem?
Cheers
 
mghikas said:
hey guys,
I have a new 3 core radiator on my 72 Demon.
Temp holds well when I’m driving about 180-190, as soon as I sit in traffic or turn my car off I get coolant coming out of my overflow hose.
I don’t have an overflow bottle.
What psi cap should I be running?
What do you guys think could be the problem?
Cheers
Click to expand...

Cheap enough to install an overflow/return bottle and a 17 pound cap --------------
 
How high are you filling the radiator ?
After the initial puke, does it continue to puke after ?

You should fill the radiator about an inch or less from the top, giving the water room for expansion. Try that, and see how it works.

My money is, you are filling the radiator to high.
 
mghikas said:
hey guys,
I have a new 3 core radiator on my 72 Demon.
Temp holds well when I’m driving about 180-190, as soon as I sit in traffic or turn my car off I get coolant coming out of my overflow hose.
I don’t have an overflow bottle.
What psi cap should I be running?
What do you guys think could be the problem?
Cheers
Click to expand...

Usually coolant being expelled at stops is low coolant circulation, or low air volume through the radiator.
Got a good fan and shroud on it?
 
My 67 273, does not have an overflow, and as others have said the fill in my rad is about an inch of so below the fill neck.

16lb cap.

I don't have anything overflowing.

( No shroud, stock 7 blade fan 1-2 stock inches from the rad.)
 
I agree, cars without overflow tank cannot be filled completely. Fill it, let it puke and it will find its own level. Should end up being about an inch down.
 
i'll ask, other than a restoration, why would someone not run an overflow?
 
kursplat said:
i'll ask, other than a restoration, why would someone not run an overflow
Click to expand...
Because it is 100 % unnecessary. If you overfill the rad, once the engine gets to the hotest it will ever get, (summer, going up a hill, with every seat filled, and the AC on if you have it), the fluid will have expanded to it's maximum, and overflowed out. When it cools down it will be at the proper level. And will never overflow again.
 
cool, so it's kind of like a summer solstice barometer that will keep pissing out a trickle of coolant until i reach the zenith, parked on the freeway for an hour when it's a 113' outside
 
kursplat said:
, parked on the freeway for an hour when it's a 113' outside
Click to expand...
If you choose to stop on the side of the Fwy (probably not a good idea), not sure why you would want to sit there for an hour but to each their own! :rolleyes:

Point is as long as you do not overfill it, it will not overflow, if you do, it will overflow till it has dumped enough fluid to equalize.

Dumping the excess will not cause your engine to overheat. If it overheats you have other issues.


If you are concerned with the environmental effects of ethylene glycol getting on the ground you had better kill all of the Greater wax moths in the world.

"The caterpillar of the Greater wax moth, Galleria mellonella, has gut bacteria with the ability to degrade polyethylene (PE) into ethylene glycol"
 
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Do a little diagnosis. Fill the radiator SLAM up. Put the cap on. Squeeze the upper hose real fast and hard while paying attention to the overflow hose. If coolant comes out, put a new cap on it.
 
I am damn near full to the bottom of the neck. Repo cap, assume 15lb. It never has puked. Shroud and fixed stock 7 blade fan with stock spacer. It’s gets plenty hot here in the summer!
 
Dana67Dart said:
If you choose to stop on the side of the Fwy (probably not a good idea), not sure why you would want to sit there for an hour but to each their own! :rolleyes:
Click to expand...
only reason i "choose" to is i live in los angeles :mad: and at the wrong time of day trying to get from work to home, (only 26mi), it can take ~90 min. so by "parked" i'm saying moving just under an idle
 
91 fwy from Weir Canyon Rd to The Block in Orange for 10 years. 17 miles 50 to 65 minutes.
(I feel your pain)

Moved to Colorado, Harmony Rd at I25 to 120th and I25 for 7 years. 50 miles 45 minutes.
 
I know what the specs say about rad cap pressure, but on a recored radiator I never use more than a 7 pound cap. If it pukes, putting a higher pressure cap is just covering up a cooling system problem in the long run and it could be too much for the repaired radiator.
 
Dana67Dart said:
Because it is 100 % unnecessary. If you overfill the rad, once the engine gets to the hotest it will ever get, (summer, going up a hill, with every seat filled, and the AC on if you have it), the fluid will have expanded to it's maximum, and overflowed out. When it cools down it will be at the proper level. And will never overflow again.
Click to expand...
If you ever take your car to the track , an overflow bottle is 100% necessary. They will boot you out without it. Maybe the OP would like to run his car down the strip. I think he should consider it, as should everyone.
 
Thanks for all the responses guys, it was just me overfilling, let the car get to operating temp and let it sit idle for about 20mins after confirming it was filled about 1 inch lower than the neck, temp kept at about 170 and no fluid overflow!
 
There you go. I have seen lots of different overflow bottles, beer bottles and my favorite so far is a skull vodka bottle.
Stainless bottles are popular too. i prefer to use an overflow,easier to check coolant level. Dont need to remove cap.
 
Tooljunkie said:
There you go. I have seen lots of different overflow bottles, beer bottles and my favorite so far is a skull vodka bottle.
Stainless bottles are popular too. i prefer to use an overflow,easier to check coolant level. Dont need to remove cap.
Click to expand...

And now you have seen a large shot shell recovery system.:D
(Which again reminded me I need to get the longer hose for)


recoverysml.jpg
 
clear puke tanks allow you to see the level of the coolant. I believe all the newer cars have have overflow tanks because they run so hot from factory for emissions (Modern truck runs 210 all day), and also most dont have radiator caps anymore, you remote fill from a T-stat housing or something. I cant see a reason not to run a tank. Pretty unobtrusive sitting there next to radiator unless your rad doesnt have a tube.
 
Rad overflow bottle is a result of environmental concerns plain and simple. Yes it does allow you to see the level without taking the rad cap off.
Newer cars have a "closed" system but most still have a rad cap just not on the rad. It acts more like an expansion tank, but it still needs to let out pressure and let in air as needed
 
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