W114 250CE Cilinder Head Gasket leak

Dear "Schrauber" mechanics,


I do have a water leakage of my cilinder head gasket and am now busy to fix it. 

I will have some more questions coming weeks, hope you people can support me.

Below the leakage itself and my first question

1) Is it a good idea to clean my cast aluminium intake manifold, the inside and outside with warm water and Dasty (Classic Fettlöser).

Greetings Marc