Although I understand how the fuel system works, I'm not sure about the valves and such that are part of the innards.

Four boats ago we rescued a Catalina 27 and spent a year rebuilding it. One of the previous owners replaced the Atomic 4 with a single cylinder BMW diesel, the first diesel we ever owned. In the learning process, Todd Dunn offered a bunch of guidance, a Racor filter, and advised adding in a outboard motor style squeeze bulb to act as a primer pump. I could change the fuel filters and after squeezing the primer bulb several times you could hear the air bubbles and finally fuel go through the return line into the tank. It was a perfect setup for quickly changing out the fuel filters and bleeding the system. I hesitate to use that setup as the "norm" because there was nothing normal about the BMW diesel.

Fast forward to the IP, it is setup with things in this order.....the tank, a DAHL primary fuel/water separating filter, an electric fuel pump, Yanmar secondary filter mounted on the engine, mechanical pump, high pressure pump, injectors, return line to the tank. I changed out the DAHL filter over the weekend and needed to bleed the system. I added about a quart of fresh diesel to the filter and reassembled it. I put a rag over the low oil pressure horn to muffle it and turned the ignition key to on, that activated the electric pump. I let it tick way for a minute or so, shut it off, then repeated two more times. I did not hear anything flowing into the tank like on the Catalina. I opened the bleed screw on the top of the Yanmar filter and activated the electric pump again. I got a steady stream of diesel fuel and even with a half dozen rags, still made one hell of a mess. My question is, will the electric fuel pump pressurize this system and bleed the air through to the fuel tank like that squeeze bulb did on the old Catalina?

BTW, the old Catalina is alive and well and living in the marina next to our club. It has since had two more owners after us, I met each and they all learned how to sail on that boat before selling and buying something bigger.