Ok, so my 2006 F350 6.0 has been rough running for 2 years. I have tried every oil additive seen here trying to cure #4 sticking injector. This week I re-tore down (having changed the standing pipe and dummy O rings earlier) and found the #4 injector spool free so I changed it out for a rebuild. Putting everything back together I tried starting it. Crank crank crank then my Edge said the High Oil Pressure to fire the injectors wasn't happening. WHAT?
Must have messed up injector O rings. Tear down, nothing found. Put back together and crank crank crank. Finally it started. A light went off, I emptied the rail oil, it needed to be refilled.
Now I'm wondering if I should have bled it out. Will it take care of itself or am I supposed to bleed the fuel/oil rail?

 

It will take care of itself.
FYI--anytime you have the HPO system open, after getting the motor restarted and warmed up, take it for three medium to hard throttle runs (40-70 mph) to help bleed the air out and prevent hard restarts.

I've learned it's pretty easy to partially prefill the oil rails to make crank time shorter BUT you risk getting trash in that may damage a spool valve because it's unfiltered. It's recommended on ALL the new diesel engines that you DO NOT prefill the oil filter OR fuel filter because of the sensitivity of the parts.