This is going to sound really dumb, but... my Euro 300D (1980) has no coolant expansion tank -- just an overflow tube down to below the radiator. I can't find any cooling system diagrams specific to a Euro 300D -- is this normal?

Thanks!

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1992 300D 2.5T
1980 Euro 300D (sadly, sold)
1998 Jetta TDI, 132K "Rudy"
1974 Triumph TR6
1999 Saab 9-5 wagon (wife's)