Brushes are the most common replaced part of any electric tool. You could drop it off at repair center for general maintance but when these machines need maintance you will know. It doesn't hurt to have an extra set of brushes on hand, they run about $5 to $8. Becareful with oil, oil attracts dirt and exxcess oil will blow out all over the paint surface. Check the manual on lubrication, to be honest when my makita starts showing its age I will buy another and keep the old one for backup.