What was found
PILOT SQUAWK: HYDR PUMP ON INDICATION, RAN CHECKLIST, UPON RESETTING CIRCUIT BREAKER, GEAR SYS INDICATION CAME ON WHEN LOWERING LANDING GEAR KNOB. RAN CHECKLIST TO INCLUDE EMERG GEAR EXTEND. CORRECTIVE ACTION: INSTALLED NEW TUBE P/N83744-139 IAW PA44-180 AMM29-00-00. COMPLETED GEAR RETRACTION TEST IAW PA44-180 AMM CH 32-30-00. OPS CHECK GOOD.