When should brake linings be replaced?

Brake linings should be replaced when they show signs of excessive wear, typically when the lining material is less than 3 millimeters thick. Additionally, if you hear squeaking or grinding noises while braking, or if you notice a decrease in braking performance, it's time to inspect and potentially replace the brake linings. Regular maintenance checks, usually every 12,000 to 25,000 miles, can help determine when replacement is necessary.