It took a lot of research and patience to figure out what kind of fuel injection pump is mounted to this engine. My Perkins 4.107/4.108 shop manual depicts two types of pumps and neither match what I'm looking at. I found the exact pump I have in Nigel Calder's book "Marine Diesel engines, 2nd edition", my favorite book right now. I bring it everywhere I go and haven't even come close to reading the whole thing yet. It describes the process for bleeding air out of the fuel line and when it gets to the part about bleeding the injector pump on page 68 there it is, the C.A.V. DPA distributor injection pump. Mine was a lot more dirty than the one in the picture but now that I can recognize what it is I've been able to make it more visible. Getting a picture of my fuel injector pump is a bit like trying to photograph big foot. All the pictures come out blurry and I was starting to think no one has ever actually seen my injector pump for real. Google how to bleed the Perkins C.A.V. pump and the advice is essentially "sell you boat and get a cabin in the woods...far away from water". These appear to be notoriously hard to bleed although simple in explanation. With that in mind it was just a matter of patience and a little bit of Diesel engine yoga before I figured out how to adjust my downward dog into a comfortable position that would allow my right hand on the lift pump and the left hand on a tool bleeding the injection pump. Two more problems after I identified the parts to the pump, I couldn't see it and I didn't have a tool (5/16" wrench) that would fit into the tiny space along with my seemingly giant hand. No problem, just install some 12v LED lights that I bought off Amazon for $15 and cut one of my wrenches in half! Below is a picture of the pump in all its glory, lit up beautifully. The two bleeder bolts are right in the middle, one above the other. The lower bleeder is mounted at a little bit of an angle as compared to the top one.
I added a lanyard to my new wrench that is going to be dedicated to bleeding the fuel line. I'm probably going to have certain tools kept in the engine compartment in custom pockets/pouches so they'll be available when needed and I'll also have them tied in to the work area so they won't go far! I've already dropped enough wrenches into the bilge and I'm trying to make retrieval not a factor. When it comes down to certain things I feel it's necessary to eliminate failure options and plan for getting the job done as efficiently as possible.
The lift pump (pictured above) is on the Starboard side of the engine and his fed from the primary fuel filter, a Racor 500FGSS filter/water separator. The fuel line then goes to the Port side remote mounted secondary filters which apparently don't have a bleeder valve and then to the Injector pump. The fuel injection is all mounted on the Port side of the engine. Bleeding the pump went really smooth once I put all the pieces into play. It took just a minute or so until I had steady fuel coming out of each bleeder bolt. Next up I need to bleed to the injectors which will require having the throttle cable connected. I disconnected it last year because it wasn't very sensitive so I'll be adding a lever into the mix to make the full throw available at the controls. That'll be one of my projects for next week, along with adding bilge pumps into the engine bilge.
Dream it. Design it. Build it. A hobbyist at heart, I'm usually asked, "Wouldn't it be cheaper and easier to just buy that?!?". Sure, but then I wouldn't understand it and appreciate it like only a do-it-your-selfer can!