When should brushes be replaced? Wilson November 12, 2020 14:18 Updated Follow As a guide, brushes should be replaced when they have become 50% worn. While the brushes will still function at 50%, the brush tension is reduced and can cause higher current draw and over-heating of the motor. Related articles Where can my product be repaired under warranty? Can DEWALT cordless tools be used around high voltage power lines? What is the warranty on my router, planer and joiner? What are the specifications for the FLEXVOLT batteries? Comments 0 comments Please sign in to leave a comment.