What was found
AFTER TAKEOFF ON FLIGHT 3915 FROM AZO TO DTW IMMEDIATELY AFTER SELECTING GEAR UP RECEIVED THE FOLLOWING MESSAGE: HYD 3 LO PRESS CAUTION - LOW PRESS QTY 100 PERCENT, NOSE GEAR DOOR OPEN WARNING, GEAR DISAGREE WARNING. ALL 3 MESSAGES EXTINGUISHED BEFORE CHECKLIST COULD BE RUN BY THE CREW. CREW DID NOT DECLARE AN EMERGENCY AND FLIGHT CONTINUED AS PLANED TO DTW. COMPLIED WITH PA05-018I SCENARIO 2 STEPS 13 THRU END. REMOVED AND REPLACED OF MLG PRIORITY VALVE DETERMINED TO BE GOOD FIX. OP CHECK OF LANDING GEAR EXTENSION/RETRACTION GOOD IAW AMM 32-30-00. C/W PA 05-018I.