When Should Brake Disc Groove Depth Require Replacement?

[McSkylar]

When the groove depth on both sides of the brake disc exceeds 1 millimeter, the brake disc should be replaced. The maximum wear limit for brake discs is 2 millimeters. Below are methods to determine when a brake disc needs replacement: 1. Check the replacement frequency of brake pads: If brake pads are replaced frequently, it's necessary to regularly inspect the thickness of the brake disc. This is because the usage of brake discs and brake pads involves relative wear, hence the importance of periodic brake disc inspections. 2. Judge based on wear conditions: Apart from normal wear of the brake disc, there can also be wear caused by the quality of brake pads and discs, as well as foreign objects during use. If deep grooves are formed due to foreign object wear, or if there are discrepancies in disc surface wear, the brake disc should be replaced promptly to avoid directly affecting driving safety. 3. Follow replacement guidelines: The service life of brake pads is 30,000-40,000 kilometers, while that of brake discs is 60,000-70,000 kilometers. Therefore, the brake disc should be replaced every two brake pad replacements.

[Wesley]

Hi, I think the depth of brake disc grooves is quite important, especially when it comes to driving safety. Generally speaking, if the groove depth exceeds 1.5mm, it's time for a replacement, but always refer to the vehicle manufacturer's manual—don't just guess. If you feel brake vibration or hear unusual noises while driving, it might be due to excessively deep grooves affecting braking force and consistency. Getting them checked during every maintenance session is a good habit, especially for cars that frequently travel at high speeds. Otherwise, the braking distance could increase, and in an emergency, you might not be able to stop in time—how dangerous is that? I've even seen a friend's car where the brake discs were completely worn out from long-term neglect, costing several times more to repair later. Early prevention saves both peace of mind and money.