What was found
AIRCRAFT RETURNED TO BASE AFTER GEAR INDICATED UNSAFE FOLLOWING RETRACTION. SAFE INDICATION ACHIEVED UPON GEAR EXTENSION. NOSE STRUT PRESSURE WAS LOW, SO STRUT DID NOT FULLY EXTEND AFTER ROTATION, THUS, WOULD NOT PROPERLY ACTIVATE UP-LIMIT SWITCH. SERVICED STRUT, PERFORMED GEAR RETRACTION TEST WITHOUT FURTHER FAULT.