My 300e has begun to leak coolant. It appears that it is coming from the highest metal fitting on the left hand side (when looking at it) of the radiator. Is this the tranny coolant pipe?

How would I fix this? I found little when I searched. Is there an o-ring inside this fitting, or is it straight metal to metal? Do I have to buy the whole replacement pipe to fix this, or worse, maybe a new radiator?

Thank you for your time.

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