How many kilometers can brake discs be replaced?
4 Answers
Brake discs generally need to be replaced when the vehicle has traveled 80,000 to 100,000 kilometers. Here are the criteria for determining when brake discs need to be replaced: 1. Observe the brake disc warning light: Normally, the brake disc indicator light is off. When the brake disc fails or is excessively worn, the light will turn on and will turn off after repair. 2. Check the thickness of the brake disc: Most brake discs have wear indicators, which are three small dimples distributed on the disc surface. Use a vernier caliper to measure the depth of the small dimples, which is 1.5mm. When the total wear depth on both sides of the brake disc reaches 3mm, it is recommended to replace the brake disc promptly. 3. Listen for sounds: If there is a metallic "grinding" or squealing noise when lightly applying the brakes, the brake pads must be replaced immediately.
I've handled quite a few vehicle repairs in my time, and brake disc replacement is actually quite complex. Most OEM brake discs need replacement around 60,000 to 100,000 kilometers, but this is just a rough guideline. It really depends on driving habits – for example, those who frequently drive mountain roads or engage in aggressive driving might need replacement after just over 40,000 km. I once serviced a pickup truck that frequently worked construction sites – it developed 1mm-deep grooves after just 3 years and 70,000 km. The most reliable method is having mechanics measure thickness with calipers during maintenance – new discs are typically 12mm thick, and should be replaced when worn below 8mm. Brake vibration or unusual noises are also warning signs – don't wait until braking distance noticeably increases before addressing the issue.
Last time I replaced my car's brake discs was at 90,000 kilometers. At that time, the steering wheel shook like a phone vibration during high-speed braking, and the inspection revealed that the brake discs were warped. I remember the mechanic said that city commuter cars can generally last between 80,000 to 120,000 kilometers, with more frequent braking in traffic jams causing faster wear. Later, I learned a practical tip: during maintenance, check for blue discoloration or obvious grooves on the disc surface. Driving more carefully can extend the replacement cycle, such as using engine braking on long descents to reduce overheating wear from prolonged braking. When replacing discs, it's best to change the brake pads as well for better compatibility.
Excessively worn brake discs are extremely dangerous as they directly impact braking distance. The minimum thickness is usually laser-etched on the disc edge, such as "MIN TH 8mm". It's recommended to inspect disc conditions every 30,000 km, paying special attention to step-like protrusions at the edges. If you notice steering wheel vibration or vehicle pulling during braking in daily driving, immediate inspection is required. Areas with strong de-icer corrosion in northern winters require extra attention - I've seen cases where discs rusted through after just 50,000 km. When replacing, opt for slotted vented discs which offer better heat dissipation. Safety is no trivial matter - don't wait until brake failure occurs to regret it.
