What was found
AIRCRAFT HAD THE HYDRAULIC LIGHT REMAIN ILLUMINATED AFTER GEAR RETRACTION. MAINTENANCE WAS UNABLE TO DUPLICATE, THE LT DOWNLOCK SWITCH WAS RESEALED AND LUBRICATED, FLIGHT CHECK UNSATISFACTORY, STILL UNABLE TO DUPLICATE ON GROUND, REPLACED NOSE UPLOCK SWITCH AND ADJUSTED LT UPLOCK SWITCH AND FLIGHT CHECKED GOOD.