how can i check the power steering fluid in my 1986 300sdl? what type of power steering fluid can i use ?also there is a black **** behind the fuse box numbered 1-7 ,what does it do? I know i have lots of quiestions ,but hey it's my first mercedes!
thanks in advance!

 

black **** is trimming plug.

 

how do i use the trimming plug ? also what kind of rpm should i be geting at idle? and how do i check the power steering fluid?thaks for the help so far!