A B767-300 PIC DEPARTS SEA WITHOUT RECEIVING MEL DISPATCH AUTH FOR A R PACK MALFUNCTION.

Narrative

AFTER PUSHBACK AND ENG START AT SEA; THE R PACK INDICATED 'INOP' WITH 'R PACK TEMP' ON THE EICAS. RESET ATTEMPTS WERE UNSUCCESSFUL. DUE TO RAMP CONGESTION; I ELECTED TO EXIT THE RAMP AND TAXI OUT TO THE RWY. WE ADVISED MAINT AND OUR DISPATCHER; VIA ACARS; OF THE PROB; EXPECTING TO DISPATCH WITH 1 PACK INOP ACCORDING TO MEL 21-51-01A AND A MAX ALT OF FL350. I REQUESTED FUEL BURN AT FL330 VERSUS FILED FL370. AT THE END OF THE RWY; WITH THE R PACK SHUT DOWN AND WHILE AWAITING THE REQUIRED DISPATCH AUTH; WE RECEIVED; VIA ACARS; FUEL BURN INFO FROM DISPATCH. TO MY LATER CHAGRIN; WE REALIZED; AFTER TKOF; THAT THIS WAS NOT DISPATCH APPROVAL; BUT AN ANSWER TO MY ORIGINAL REQUEST FOR FUEL BURN IN ADVANCE OF APPROVAL. AS THESE LINKING EVENTS USUALLY GO; WE RECEIVED A L ENG BLEED VALVE LIGHT DURING THE LATTER STAGE OF THE TKOF ROLL. THE TKOF WAS CONTINUED. WE WERE THEN IN POS OF HAVING NO PRESSURE SOURCES. I ASKED FOR AND RECEIVED A LOW ALT HOLD DOWN AND EXCELLENT ASSISTANCE FROM ATC WHILE WE TROUBLESHOT THE SIT. AFTER CONSULTING WITH MAINT CTL; IT WAS RECOMMENDED THAT WE TURN THE R PACK BACK ON. IT; OF COURSE; WORKED PERFECTLY. THE L BLEED WAS A REPEAT GRIPE THAT HAD BEEN SUPPOSEDLY CLRED BY MAINT IN SEA. ALL PARTIES AGREED THAT IT WAS SAFE TO PROCEED TO OUR DEST. ALTHOUGH THE FLT CREW PLACARDING WITH DISPATCH APPROVAL OF THE ORIGINAL PROB WOULD HAVE BEEN APPROPRIATE; MY EXPECTATION OF THAT APPROVAL WAS NOT. ALTHOUGH COORD HAD BEEN INITIATED AND WOULD HAVE BEEN RECEIVED; IT WAS NOT COMPLETE.