What was found
AFTER THE LANDING GEAR HANDLE WAS MOVED TO THE DOWN POSITION BOTH MAIN LANDING GEAR INDICATED DOWN AND LOCKED BY A GREEN LIGHT, HOWEVER THE NOSE LANDING GEAR INDICATION REMAINED RED. THE PILOT TERMINATED HIS APPROACH AND INITIATED A CLIMB TO EVALUATE THE SITUATION. THE PILOT CONTACTED SALT LAKE CENTER AND DECLARED AN EMERGENCY AND SQUAWKED 7700. ATC GAVE HIM A DISCRETE SQUAWK CODE WHICH HE ENTERED. CONTINUED HIS CLIMB TO 16,000 FEET AND RAN THROUGH THE EMERGENCY CHECK LIST. ACTIVATED THE HAND PUMP 5-8 TIMES AND THE NOSE GEAR GREEN LIGHT ILLUMINATED AND THE RED LIGHT WENT OUT. CONTINUED ON TO AND MADE AN UNEVENTFUL LANDED AT KSLC. THE GROUND SERVICE VALVE WAS REPLACED AND THE HYDRAULIC SYSTEM WAS SERVICED UNDER WORK ORDER M3601.