Still relatively new to the detailing game and having gathered a small collection of dual action and rotary polishers, most of them with access ports to replace the brushes, how do you know when it's time to replace the brushes?
Are there telltale signs like motor whine, rattling ball-bearings. a burning smell? Or is it more just by intuition? If you check the brushes periodically, how many hours do you let your polisher clock before checking?
Thanks in advance.