What was found
(CAN) WHILE LANDING GEAR WAS BEING EXTENDED DURING AN APPROACH, LANDING GEAR DID NOT COME OUT AFTER A FEW TRIES (GEAR UP, GEAR DOWN), IT DID FINALLY EXTEND. THE AIRCRAFT WAS CHECKED AND IT SEEMED THAT THE ENGINE WAS FORCING DURING RETRACTION. THE BRUSHES WERE CHECKED AND 2 OUT OF 4 WERE FOUND FAILED. THESE WERE REPLACED. A FEW MORE RETRACTIONS WERE TRIED AND EVERYTHING RETURNED TO NORMAL.