I've had very good luck using the Sam's Club degreaser to clean any of the various valves, set the sprayer on "STREAM" and fill it, let sit a day or two then rinse it out with tap water, good to go .

Nothing wrong with servicing a good used part ~ that's how actual Mechanics do things not just throw money at every problem .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better