2001 Silverado Coolant Overflow tank question.

[trentkoch123]

About a year ago, I got my Coolant overflow tank and radiator replaced (it was badly yellowed and there was a portion of the walls that were thinning and it needed replacing) and I've noticed some issues with the coolant levels as of recent. I will attach a few screen caps of a video, showing exactly what I'm talking about, but to summarize it, the tank seems to be "Walled" unlike the other one, where the left side of the tank where the main radiator hose connects drains when the truck is started, leaving the right side of the tank at a normal level. Also, like i said, the left side is EMPTY on start, so i am not sure if  that means i have an air bubble somewhere in the system or if it is because of the left half that drains and the right half that does not

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