What was found
PILOT REPORTED THE 'HYDRAULIC PRESSURE' LIGHT WOULD NOT EXTINGUISH WHEN THE LANDING GEAR WAS RETRACTED. RED TRANSIT LIGHT EXTINGUISHED. GEAR CYCLED 5 TIMES IN THE AIR WITH NO CHANGE. AIRCRAFT RETURNED TO STATION. AIRCRAFT PLACED ON JACKS. GEAR CYCLED 5 TIMES. COULD NOT DUPLICATE DISCREPANCY. HYDRAULIC PRESSURE SWITCH, P/N 9910287-10, REPLACED. GEAR CYCLED 12 TIMES, NO DISCREPANCIES. AIRCRAFT TEST FLOWN. 'HYDRAULIC PRESSURE' LIGHT WOULD NOT EXTINGUISH. AIRCRAFT RETURNED TO STATION. HYDRAULIC MANIFOLD ASSEMBLY REPLACED. GEAR CYCLED 6 TIMES. AIRCRAFT TEST FLOWN AND RELEASED FOR FLIGHT. SUSPECT MANIFOLD ASSEMBLY, P/N 9910188-1, LEAKING INTERNALLY.