What was found
DURING A ROUTINE ANNUAL INSPECTION, THE MLG HYD POWER PACK MOTOR WOULD NOT SHUT OFF AT THE END OF THE RETRACT OR EXTEND CYCLE WHILE ON JACKS USING ONLY SHIPS ELECTRICAL POWER (24V). THE MLG CYCLED PROPERLY DURING FLIGHT AND PILOT NOTICED NO DISCREPANCIES BEFORE THE INSPECTION. T/S REVEALED MLG SYSTEM FUNCTIONED PROPERLY WHEN AT 26V WERE APPLIED TO ACFT. NOTE: ACFT SYS IN-FLIGHT VOLTAGE IS 28V. MLG HYD POWER PACK REMOVED FROM ACFT AND SENT OUT FOR O/H. O/H SHOP CONFIRMED MOTOR AND PUMP COULD NOT FUNCTION PROPERLY, NOT ABLE TO BUILD UP PRESSURE. SUBMITTER SUGGESTS SIMULATING ALTERNATOR 'OUT' DURING ANNUAL TO SEE IF ACFT SYSTEMS WORK PROPERLY.