What was found
ON DEPARTURE FROM PIT, HAD A "GEAR DISAGREE" MESSAGE AND A RED NOSE GEAR INDICATOR. RAN CHECKLIST AND RETURNED TO PIT. CAPTAIN CALLED ON THE GROUND AND STATED THEY HAD A NOSE GEAR DISAGREE, NOSE GEAR WOULD NOT RETRACT, THEY FOLLOWED THEIR QRH AND LANDED AT KPIT WITHOUT INCIDENT. REPLACED NLG SELECTOR VALVE, PN 750006000, SN OFF 1624, SN ON 1150T. C/W IAW CRJ200 AMM 32-33-10-000-801. C/W BLEED AND LEAK CHECK OF ASSOCIATED SYSTEMS IAW AMM 29-10-00-870-010. PERFORMED SEVERAL EXTENSION/RETRACTION CYCLES, WITHOUT DISCREPANCY. OPS CHECK OF LANDING GEAR SYSTEM GOOD.