Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
The oil pump is just not very good at pumping air, if the onward system is resistant (the graphogen is an effective seal in the bearings) it just can't pull the oil into the pump head sufficiently. By cranking with filter removed it prevents it building air pressure, then once you see the oil arrive into the filter chamber the pump head and pipe both side of it will be purged such that it'll pump the oil easily. It will usually take only about 30 sec further to fill the galleries with the filter back on.
