Needing to purge air to start each time after elec. lift pump install

Yes, the line is connected. A friend recommended purging the line at the injection pump, then after it's running, purge each line at the injectors- he thinks that will eliminate the rest of my problems. I think it is possible to have a suction leak at the line going from the lift pump to the filter manifold, since at the manifold it has a rubber compression seal inside the b-nut. Maybe I'll re pack it just to be sure. -Jeffy.

I do have the line from the filter to the #1 injector connected, but is there another return line? These hoses are old and all need to be replaced. I purge every thing before starting but it seems like the fuel drains back after the truck sits turned off. The fuel filter is about half full. I found that I had caused a leak by adjusting the injector pump timing, and had loosened the fuel supply line in the process. I just discovered that this morning(what an idiot!). None the less, I still have an air leak which also affects over the road driving. I will try bleeding everything again, and hope I just wasn't thorough enough last time. -Jeffy.

My original lift pump is not part of the fuel system any more, only the electric pump. I have no fuel leakage, but when I remove the cap from the priming valve, there is fuel wetness present. The cap is the type of brass with rubber seal insert used on military airplane tires. I am suspecting the core needs to be replaced. After I drove it last, I bled the injector lines again, since I had an incident of no response to throttle input while climbing a grade. -Jeffy.

Thanks once again for all the tips, always educational!

I replaced the priming valve core at the filter. it's the same thing you'll find in your wheels. Mine wasn't very tight, but I replaced the core anyway, a bit tighter. Today the truck ran well without any more air bleeding. If bleeding should become necessary, the electric lift pump makes the process easier and a 1-man job. To other non-experts like myself: make sure there is fuel pumping before depressing the priming valve, or you'll just be letting more air in! Thank you experts for helping me with this problem. It seems like I might not need a injection pump just yet, but if it weren't for your advise I'd probably had bought one unnecessarily. -Jeffy.