What was found
PILOT SQUAWK: LANDING GEAR FAILURE. USED EMERGENCY GEAR EXTEND. AFTER TAKEOFF, WE GOT 3 RED WHEN WE PUT THE GEAR UP. WE TRIED AGAIN AND IT WENT UP. FAILED WHEN WE TRIED TO PUT GEAR DOWN. CAS MESSAGE: HYDRAULIC PUMP ON, GEAR SYS. CORRECTIVE ACTION. REPLACED HYDRAULIC LINE WITH NEW P/N 83744-139 IAW PA44-180 AMM 29-10-00. TORQUED FITTING AT HYDRAULIC PUMP FOR LANDING GEAR, CLEANED, SERVICED AND CYCLED LANDING GEAR TO PURGE AIR FROM SYSTEM IAW PIPER PA44-180 AMM 12-10-00 AND 32-30-00.