Posted in the Diesel board wrt leaking cover at B-1 Reaction valve. Helpful poster(s) ID'ed the valve cover, and pointed out seals on valve assy are the likely leak source.

Car is a 1983 300SD, auto transmission.

Is there anything special about removing the valve and either exchanging with a new valve or exchanging the valve seals (o-rings) and plastic end cap? For example, does orientation (axial rotation) matter? What is the torque spec for the cover/cap -- I couldn't get the cap (12mm in-hex fastener) to rotate.

Removing that allen plug is the hardest part. After that you will need to PULL out the reaction valve & install the 2 o-rings. USE vasoline to secure the guide pin!

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