I just remembered a very good tip. Do yourselves a favor and get the small hose between the water pump and the head from MB or from someone who can order it by p/n. The two ends are different sizes! Not by much, but enough where I suspect this is where a lot of leaks come from when people replace this hose with a piece of generic hose.

I happened to be talking to a dealer parts rep about some small parts and he told me about this. If you get the mb part you'll see what I mean about it being an easy source of trouble if you are unaware. The difference is not much.