AN MD83 TECHNICIAN REPLACING A R WING INBOARD BOOST PUMP WITH NO PWR ON THE AIRPLANE WAS QUESTIONED BY AN FAA SAFETY INSPECTOR WHY THE CIRCUIT BREAKERS WERE NOT PULLED AND TAGGED. MAINT MANUAL REQUIRES CIRCUIT BREAKERS PULLED.

Narrative

ACFT HAD BEEN IN HANGAR FOR A FEW DAYS WITH THE PROB OF THE CTR TANK NOT FEEDING THE ENGS WHEN IT REACHED 4000 LBS OF FUEL. THE VOLUTE HAD BEEN CHANGED THE DAY OF AND THERE WAS SOME CONFUSION AS TO WHETHER THAT HAD REPAIRED THE PROB OR NOT. IT WAS DETERMINED THAT PERHAPS WE SHOULD CHANGE THE INBOARD MAIN TANK BOOST PUMP ON THE R WING; WHICH I DID; AND THE PWR WAS OFF THE ACFT BECAUSE THERE WAS NO OTHER WORK GOING ON WITH MYSELF BEING THE ONLY ONE WORKING ON THE AIRPLANE. AT THIS POINT I FOUND OUT THAT THE NEW PUMP I WAS PLANNING ON INSTALLING HAD A BENT PIN ON IT AND COULD NOT BE INSTALLED. WE THEN ORDERED A NEW PUMP; WHICH WE DIDN'T HAVE IN STOCK AND WOULD BE SOME TIME BEFORE WE GOT IT. A FEW HRS LATER; I WAS TOLD BY MY SUPVR THAT THE FAA WAS ASKING WHY THE CIRCUIT BREAKERS FOR THE BOOST PUMPS WERE NOT PULLED. SO WITH PWR OFF THE AIRPLANE I FAILED TO PULL THE CIRCUIT BREAKERS AS THE MAINT MANUAL SAYS I SHOULD HAVE DONE. I THEN IMMEDIATELY PULLED THE APPROPRIATE CIRCUIT BREAKERS AS REQUIRED IN THE MAINT MANUAL AND EXPLAINED WHAT I HAD DONE TO THE INSPECTOR.