What was found
EVENT SUMMARY STATED GEAR DISAGREE. REMOVED AND REPLACED MLG PRIORITY VALVE IN REF TO CRJ MM 32-32-15, NO FIX. FOUND AIR IN NR 3 HYD SYSTEM, DRAINED AIR AND SERVICED HYD SYSTEM IAW CRJ AMM 12-12-29. CREW WROTE THE FOLLOWING, LEFT GEAR UP DISAGREE ON RETRACTION, CLEARED ITSELF IN 1 MINUTE, HYD PUMP 3 WAS 2300 LBS. D/L CODES FROM PSEU AND A HARD FAIL WAS DISCOVERED ON LT MLG CODES WAS LEFT GEAR UPLOCK FAR. DID NOT HAVE A CHANCE TO DO GEAR SWINGS BUT BELIEVED GEAR WAS SLOW TO COME UP. FOUND NR 3 ACCUMULATOR LOW, SERVICED NR 3 ACCUMULATOR IAW CRJ AMM 12-12-29 D/L LOADED CODES FROM PSEU AND RESET PSEU. GEAR SWINGS OP CHECK GOOD. MLG SELECTOR VALVE, NO LEAK NOTED.