What was found
CREW REPORTED THAT DURING TAXI OUT, AN ACRID ODOR DEVELOPED AND SMOKE OF SOME SOURCE WAS VISABLE IN THE JUMPSEAT AREA. CREW ISOLATED AIR CONDITIONING PACK AND RETURNED TO THE BLOCKS. ODOR AND SMOKE DISSIPATED ONCE PACK WAS SECURED "OFF". FOUND A PARKING BRAKE HYDRAULIC LINE LEAKING IN THE AIR CONDITIONING PACK AREA. SECURED A LOOSE B-NUT AND THEN RAN AIR CONDITIONING PACKS AND VERIFIED NO SMOKE OR VISABLE SMOKE. CREW CONTINUED ON SCHEDULED FLIGHT.