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Running high pressure in cooling system, overheating.; Cooling System
Topic Started: Dec 6 2016, 05:07 PM (373 Views)
Jim R Caretaker
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Is this thing on...
[ *  *  *  *  * ]
So I'm understanding that the cooling system is closed... But I can't keep water in mine.

I've done some things. New water pump, thermostat, radiator cap, flushed the system...

New head gasket...

Runs good, just will not hold water. One visible leak from where the heater hose connects to heater core at the firewall... Inside the engine compartment. And only after pressure builds up in the cooling system.

Anyone... Thanks in advance

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monzanut
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Drip under Pressure

If possible, you need to do a leak test with one of these...http://geometroforum.com/topic/8039488/1/ , the tester I started topic with. You can pressure the system up and fix any leaks you see. Also look for dampness on passenger floor carpet for heater core leak, sticky fog in the cab when you have heater core leak, smell of sweet antifreeze at the exhaust pipe for internal engine leak into cylinder, chocolate looking oil when leaking into engine.
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MarkyMayhem


"One visible leak" - fix it! I was just having some over-cooling issues - cracked hose on the back of the throttle body finally blew out. Fixed it, fixed the issue. Yes - overcooling from a cracked hose.
You're symptoms sound like a head gasket but.. You did that so...
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monzanut
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Drip under Pressure

When you did the head gasket, did you have the head checked for warp?
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freegeo
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Jim R Caretaker
Dec 6 2016, 05:07 PM
So I'm understanding that the cooling system is closed... But I can't keep water in mine.

I've done some things. New water pump, thermostat, radiator cap, flushed the system...

New head gasket...

Runs good, just will not hold water. One visible leak from where the heater hose connects to heater core at the firewall... Inside the engine compartment. And only after pressure builds up in the cooling system.

Anyone... Thanks in advance

Quote:
 
New head gasket...


What was done when the head gasket was replaced? The head and block surfaces checked for flatness?

Any known visible leaks need to be taken care of. Then see if the engine still loses coolant.

Quote:
 
Runs good, just will not hold water.


You are not just running water in the cooling system right? You mean a coolant mixture instead?
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Jim R Caretaker
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Is this thing on...
[ *  *  *  *  * ]
freegeo
Dec 8 2016, 12:35 PM
Jim R Caretaker
Dec 6 2016, 05:07 PM
So I'm understanding that the cooling system is closed... But I can't keep water in mine.

I've done some things. New water pump, thermostat, radiator cap, flushed the system...

New head gasket...

Runs good, just will not hold water. One visible leak from where the heater hose connects to heater core at the firewall... Inside the engine compartment. And only after pressure builds up in the cooling system.

Anyone... Thanks in advance

Quote:
 
New head gasket...


What was done when the head gasket was replaced? The head and block surfaces checked for flatness?

Any known visible leaks need to be taken care of. Then see if the engine still loses coolant.

Quote:
 
Runs good, just will not hold water.


You are not just running water in the cooling system right? You mean a coolant mixture instead?
Yeah 50/50
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Dystopiate666
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Tree Banger

Pressurized cooling system means you have a compression leak into the cooling system, it really can't come from anywhere else. Best case scenario, you get to do the head gasket again.
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freegeo
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The cooling system is pressurized.
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myredvert
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myredvert

Quote:
 
Pressurized cooling system means you have a compression leak into the cooling system, it really can't come from anywhere else.
Not necessarily. It depends on exactly how pressurized the system is getting. The cooling system is designed to normally pressurize itself as the coolant temperature increases up to the 13 psi cap rating in order to increase the boiling point comfortably above the normal system operating temperature.

The boiling point will increase by a little under 3F for every psi of pressure, so a 50/50 coolant:water mixture with a 0 psi boiling point of roughly 226F will not boil until roughly 259f under 12 psi pressure.

After correcting the already identified heater hose coolant leak, measuring the system pressure, observing the coolant flow with the cap off as the coolant heats up and the thermostat opens and watching for bubbles, or performing pressure testing the system can help identify and locate an abnormal pressure source and/or internal or external system leaks.
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Dystopiate666
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Tree Banger

Perhaps I should have said excessive pressure. When my head gasket went, I was springing leaks around the water pump, we won't know until he fixes visible leaks. If symptoms persist with no visible leaks....
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myredvert
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myredvert

Quote:
 
Perhaps I should have said excessive pressure.
I'm with you. :thumb

that's the issue with descriptions that aren't specific - "high pressure" in the system could mean a lot of different things to different people, and without knowing specifically what the pressure is it's hard to picture what may (or may not be) wrong in the system.
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Jim R Caretaker
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Is this thing on...
[ *  *  *  *  * ]
Dystopiate666
Dec 8 2016, 08:35 PM
Pressurized cooling system means you have a compression leak into the cooling system, it really can't come from anywhere else. Best case scenario, you get to do the head gasket again.
Thanks in advance
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