Yep be sure the o-ring between the shutoff and the pump is good. Also don't forget the o-ring on the 'pool strainer' pre filter. If any air gets in the system on this engine, you are going to have a hard time. Get an LED flashlight and shine it behind the clear hoses and look for bubbles after it has sat. Park it nose up to enhance the process.

You may want to think about replacing the SOV due to age, mine had a crack in it, and it was leaking fuel out the connector.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech