"Magic" is a great answer -- quit while you're ahead! 
It sounds like the fuel lines from the Racor to the injectors have remained full and you just haven't, for some reason or other, gotten any air into the system. That happened to me one time, and I wish it would again!
Think of the fuel lines as a FULL cup or glass with the fuel filter sitting on the top of the lip of the cup: you're replacing the fuel filter, which is at the top -- this isn't removing any fluid from down below (in the glass). If you fill the Racor filter by gravity from the tank (opening the vent on the Racor housing) or by pouring diesel into the bowl, you may not get any air into the system and never have to bleed at the secondary filter.
Good work! Actually I think you've found the trick: I don't fill the bowl, I use the electric pump to do that, so I'm actually introducing air into the system. I'll try your way the next time, should save a lot of work.

It sounds like the fuel lines from the Racor to the injectors have remained full and you just haven't, for some reason or other, gotten any air into the system. That happened to me one time, and I wish it would again!
Think of the fuel lines as a FULL cup or glass with the fuel filter sitting on the top of the lip of the cup: you're replacing the fuel filter, which is at the top -- this isn't removing any fluid from down below (in the glass). If you fill the Racor filter by gravity from the tank (opening the vent on the Racor housing) or by pouring diesel into the bowl, you may not get any air into the system and never have to bleed at the secondary filter.
Good work! Actually I think you've found the trick: I don't fill the bowl, I use the electric pump to do that, so I'm actually introducing air into the system. I'll try your way the next time, should save a lot of work.