Hello all.
I continue reviewing my recently acquired 190E 2.3 (8valve, 1992).
I have found that in the radiator's upper hose, the one that goes to the expansion tank and also to the bottom of the engine, has a kind of connector on it, but it is not connected.
In this photo you can see what hose am I talking about. The connector is in the vertical portion of the hose. (not visible in this photo).

Someone knows what is it and why is it unconnected?

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