As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST AFTER TAKEOFF, THE 'RUDDER PRESSURE' AND 'RUDDER FULL PRESSURE' CAUTION LIGHTS ILLUMINATED. THE CREW ELECTED TO RETURN TO THE ORIGINATING AIRFIELD. AFTER THE LANDING GEAR AND FLAPS WERE EXTENDED, THE CAUTION LIGHTS EXTINGUISHED. BOTH HYDRAULIC SYSTEMS QUANTITIES REMAINED NORMAL. MAINTENANCE DISCOVERED THE NR 2 HYDRAULIC SYSTEM HAD AIR IN THE SYSTEM. SYSTEM WAS BLED AND REPLENISHED. AIRCRAFT WAS RUN ON THE GROUND AND RUDDER ACTUATED SEVERAL TIME WITHOUT ANY CAUTION LIGHTS ILLUMINATING. AIRCRAFT WAS THEN RELEASED FOR SERVICE.