mark cross

here comes another simple question, I hope! On my D-7, 17a, What is fluid in compartment under the fuel rack hou,sing. There is large hexa plug with grouve for a large screwdriver. In it was, its seems to me to be, desiel. Considering that the cam and lifters for the fuel pumps would need crankcase oil or hyd oil. I know diesel has a higher oil ratio. Thank you all for your info..

Should be same grade as main engine oil in the injection pump sump. Fill to the top of the filler elbow.

Tank you so much.