So do I need to release the bubbles valve on the coolant system often or only when I add fluid?????

Asked by Apr 22, 2017 at 03:49 AM

Question type: Maintenance & Repair

OK, I recently got a 1996 Chevy Lumina. I was told I have to release the air bubbles from the valve at the front of my block. This is concerning my coolant system. I need more info. I don't like the idea of not having all the facts. Machines all need cooling but this is different from what I'm used too.

4 Answers


The valve you are talking about is only opened up when filling the cooling system after it has be drained. When refilling the cooling system that valve is opened up to release the air from the engine block, once coolant is coming out of that valve when refilling the cooling system, it gets closed off. Then the cooling system gets purged from the rest of the air trapped inside. Once the cooling system is purged from all the air pockets, it does not need to be done again, unless of loss of coolant due to a leak in the system, or the cooling system had be drained down some for any reason. Just keeping the coolant reservoir topped off, checking it when the engine is cooled down, is all you need to do until a problem arises. Trapped air can make the engine run hot, along with meany other reasons. Here is a video on how to purge the cooling system...

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Best Answer Mark helpful

If you have to continually bleed out the air then chances are very high that it is not air but combustion gasses due to a blown headgasket or a cracked cylinder head, you may also notice a slight engine miss when first started up but disappears quickly, then after a while as the leak progresses you will notice steam out he tail pipe for a few seconds and then a loss of coolant with no external leaks.

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Thank U both for this info. It will make for an easier fix. I will have to watch for loss of coolant & steam, that is great knowledge. was taught engines on older cars with out all this computer stuff. THANK YOU SO MUCH!!


Your welcome.

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