What was found
(CAN) AFTER START-UP AT PUSH BACK THE PURSER NOTIFIED THE FLT DECK CREW OF FUMES IN THE CABIN. THE PASSENGERS WERE DEPLANED AND THE AIRCRAFT WAS RETURNED MAINTENAN CE TO IDENTIFY AND DETERMINE THE SOURCE OF THE PROBLEM. MAINTENANCE FOUND A PIN HOLE IN THE TAIL SKID ACTUATOR SUPPLY LINE. THE LINE WAS REPAIRED AND THE AIRCRAFT GROUND CHECKED WITH ENGINES, PACKS AND GASPER OPERATING WITH NO INDICATION PRIOR TO RETURN TO SERVICE