Radiator not full but reservoir is?

Rhrrsn

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I just did a coolant flush after finding out It had dexcool in it. I replaced it with Zerex G05 and I looked in my radiator a few days ago and to my surprise it was not full after doing the flush around a month ago. My reservoir however was still full. I added some to the radiator and went about my day. I checked today and it was not full again. I have no overheating problems but I want to make sure I’m not causing any problems either. I did not burp the system as I was under the impression TJ’s would automatically burp itself. What could be the case for missing coolant in the radiator? If I need to burp it what steps do I take? Thanks everyone!
 

BuildBreakRepeat

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I just did a coolant flush after finding out It had dexcool in it. I replaced it with Zerex G05 and I looked in my radiator a few days ago and to my surprise it was not full after doing the flush around a month ago. My reservoir however was still full. I added some to the radiator and went about my day. I checked today and it was not full again. I have no overheating problems but I want to make sure I’m not causing any problems either. I did not burp the system as I was under the impression TJ’s would automatically burp itself. What could be the case for missing coolant in the radiator? If I need to burp it what steps do I take? Thanks everyone!
Best solution is continue to top off the radiator in the coming days until it stays full. They might be self burping - but it is super easy to help it along.
 

Jerry Bransford

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Radiator cap on tight? Proper 18 lb. pressure rating? Cap not so old its spring or seal have seen better days?
 
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toximus

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You need to burp it. Remove the cap and wait for the engine to come to temp. Having a burping funnel helps.
 

Jerry Bransford

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You need to burp it. Remove the cap and wait for the engine to come to temp. Having a burping funnel helps.
The TJ's cooling system is self-burping through the top radiator hose. Trapped air eventually makes its way up through the thermostat and ends up in the top of the radiator.
 

TJ2

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It's been self burping if your reservoir is getting emptier every time you check.
Edited: If it stays full however, your rad cap might be too tight (change it 15 psi +/-3) and then you need to burp it to help a bit of your peace of mind.
 
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Goatman

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Is the overflow getting fuller after you add to the radiator or does the fluid just keep disappearing? At some point you might want to consider the head gasket not sealing up the water passages completely.
 

TJBrad04

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Get a new quality cap with OE spec psi and make sure the hose between radiator and reservoir is perfectly sealed... Probly just replace it. If the hose has a leak it will fill the reservoir fine but will pull air instead of fluid when the system cools and condenses.