What was found
(CAN) BEGIN QUOTE, CALLED AND NOTIFIED THAT AIRCRAFT WAS RETURNING DUE TO AN LDG DISAGREE WARNING MESSAGE. REMOVED AND REPLACED LANDING GEAR SELECTOR VALVE IAW AMM 32-32-10 LEAK CHECK GOOD. CW LANDING GEAR EXTENSION AND RETRACTION IAW AMM 32-30-00, OPS CHECK GOOD END QUOTE: INFORMATION TAKEN FROM AIRCRAFT MAINTENANCE LOG BEGIN QUOTE: DISC: AFTER TAKEOFF AND UPON GEAR RETRACTION, RECEIVED "GEAR DISAGREE." IT APPEARED THAT THE NOSE GEAR DID NOT RETRACT, PERFORMED AOM CK-LIST, NORMAL GEAR INDICATION RETURNED TO YUL NORMAL LANDING. REMOVED AND REPLACED LANDING GEAR SELECTOR VALVE IAW AMM 32-32-10 LEAK CHECK GOOD PERFORMED OP CHECK OF LANDING GEAR EXTENSION AND RETRACTION IAW AMM 32-30-00. OPS CHECK GOOD END QUOTE, (TC NR 20090118001).