Alpha, I'm sorry to tell you this, but most likely the pump is trashed. The metal filings probably galled the housing and ruined the seal between the impellers and the housing. No seal, no pumping oil. Without tight clearance, the pump cannot make enough vacuum to prime itself or if it did manage to pickup some oil, there would not be enough pressure to do any work.
The clearances inside the pump are very tight and it doesnt take much damage to ruin a hydraulic pump of any kind.
Make sure you get all of the shavings out of the sump before you install a new pump, or you will be doing this again. /forums/images/graemlins/frown.gif
Sorry for the bad news, hope I'm wrong.
Nailerguy