Mine's too small!
I have an '85 300TD wagon. The majority of the washer system was missing from the car when I bought it. I ordered everything from MBParts.com, the numbers on the reservoir and cap match, the cap seems to be the same cap/same-sized cap as the one on the rear reservoir, but it's way too small.
Cap # 123 869 01 72
I forget the reservoir #, but I think it's also a 123 869#.

My best guess is, the front reservoir takes a bigger cap. Or, I've go the wrong reservoir. It doesn't look wrong, though.

Any ideas?

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