I just did that on my W210 - the seals are O rings, I used two from my metric assortment I have - autozone etc sells them.

If you dont want the assortment you can take the two O rings to oriellys or autozone and buy 2 O rings from their O ring selection.

costs not more than a dollar.


In my car the washer tank was plastered in salty crust from the inside, which I have deduced to be coolant remains. My car's O rings were flattened and the whole thing was loose due to that and I was losing a glassfull of coolant once every 3 months or so.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)