What was found
LEFT MLG LANDING GEAR RETRACTION: AFTER TAKEOFF, SELECTED GEAR HANDLE UP. THE GEAR REMANDED DOWN AND LOCKED, 3 GREEN INDICATION. USED THE CESSNA CHECKLIST: LANDING GEAR DOWN ANNUNCIATOR DISPLAYS WITH GEAR RETRACTED. PER THE CHECKLIST: EMERGENCY GEAR EXTENSION WAS USED. REMOVED MLG CONTROL HANDLE ASSY & REPLACED WITH NEW MLG CONTROL HANDLE ASSY IAW TROUBLESHOOTING GUIDE IAW AMM 32-30-00. REMOVED SOL OPEN LOADING BYPASS VALVE FROM MAIN HYD MANIFOLD & INSTALLED AN OVERHAULED SOL OPEN LOADING BYPASS VALVE IAW AMM 29-11-06. OPS CHECKED GOOD. ALL WORK COMPLETED IAW AMM 29-11-06 & 32-30-00.