What to Do When Brake Discs Develop Grooves?

[DiCassidy]

When brake discs develop grooves, the decision to replace them should be based on the depth of the grooves. Below are specific recommendations: 1. If the grooves are relatively minor, the brake discs can be removed and professionally resurfaced using specialized equipment to smooth out the surface. 2. If the grooves on the brake discs are deep, it is advisable to directly replace them with new brake discs. 3. Under normal usage, a car's brake discs can last between 80,000 to 100,000 kilometers. Brake pads are also components that require regular inspection and replacement, typically every 60,000 kilometers. During routine maintenance, it's recommended to have a technician check the condition of the brake discs and the remaining thickness of the brake pads to promptly identify any issues if they arise.

[StKathryn]

Last time my car also had the issue with brake disc grooves, which was quite scary—the steering wheel would shake during high-speed braking. After checking, I found that the brake pads were completely worn out, and the metal parts directly scratched the brake discs. The most troublesome part is that minor grooves usually don’t need attention, but if they’re deeper than 1 millimeter, you’ll need to machine them smooth or replace the entire disc. Normally, you should listen for any squeaking noises when braking—that’s the brake pad wear indicator reminding you. I recommend checking the brake pad thickness every 5,000 kilometers by removing the wheels. If there’s only 3 millimeters left, it’s time to replace them. Otherwise, trying to save a little money might end up costing you a lot more to repair the brake discs, not to mention the safety risks.

[Gatsby]

The key to brake disc grooves is to assess their severity. I once had a case where the mechanic measured it with calipers—only 0.5mm deep, so I kept using it. But if a small stone gets lodged and gouges a deep groove, or if the entire disc surface becomes pitted, it must be addressed. When I replaced my brake discs, I learned that OEM discs are considered worn out if thickness loss exceeds 2mm. Now, during every maintenance check, I make it a habit to inspect the inner side of the wheels, especially after driving on muddy roads post-rain, as gravel tends to get trapped between the pads and score the disc surface.

[SanHaley]

Brake disc grooves should not be ignored. I've seen cases where people delayed repairs until the entire braking system was ruined. The main issues lie in poor-quality brake pads or improper installation - hard material particles embedded in the pads will score the disc surface. Last time my car had severe grooves, even the brake pedal became extremely stiff. There are only two solutions: minor cases can be fixed with disc resurfacing (professional repair shops have special lathes for this), while severe cases require replacing both discs and pads together. Nowadays I always choose brake pads with soft metal markers - they make audible warnings when worn down to the alert line.