This is a very helpful thread, *however*, there is one crucial hose that is missing. People (non-professional technicians) typically discover it *after* they've drained the cooling system and they suddenly realize that they are in trouble since they have no such hose.

I am referring to the short (2"?) hose that is situated between the thermostat housing's bottom (vertical, not diagonal) port and the port adjacent to the water pump. See the attached pics. 1-3.

So, what to do when one seeks to replace this hose? Well, I believe (but cannot prove) that M-B does not sell the hose. Thus, one uses a piece of 1-5/8" hose (see attached pic. 4). When cutting the length needed, seek to replicate the length as best you can - there is not a lot of acceptable latitude to deviate.

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