Why do newly replaced brake pads make a sharp noise?

[IsabellaLee]

The reasons for the sharp noise from newly replaced brake pads are: 1. The contact surfaces do not match, as the old brake disc was not resurfaced when installing new brake pads; 2. There is a defect in the brake system itself, causing the brake pads to only partially contact the brake disc, which increases the pressure per unit area during braking and results in abnormal noise. It is recommended to inspect components such as the caliper and guide pins. The method for replacing brake pads is: 1. Open the engine compartment and check the brake fluid level to prevent overflow during replacement; 2. Remove the wheel where the brake is located; 3. Remove the caliper bolts and take out the old brake pads; 4. Install the new brake pads and tighten the guide bolts.

[EvangelineAnn]

I've encountered this issue quite a few times! New brake pads are just like new shoes that need breaking in—they tend to squeak a lot when first installed. The main reason is that the brake pads and rotors haven't properly matched yet, and there might be some hard spots or unevenly distributed metal particles on the pad surface, causing noise when they rub. I recommend pressing the brakes a few more times and applying slightly harder braking while driving (safety first) to help them settle in properly. If the squeaking persists after driving 100-200 kilometers, it could be an installation issue, such as improperly applied anti-noise paste or misaligned shims, and you should go back to have the mechanic readjust them.

[DiEloise]

As someone who works with cars all year round, I believe the key lies in the installation process and the quality of the parts. If new brake pads aren't chamfered, the hard edges can cause a lot of noise when rubbing. Similarly, if old grooves on the brake discs aren't polished before installing new pads, they might not mesh well together. Additionally, cheaper brake pads often contain more hard materials, making the noise more noticeable. You can check the brake disc surface yourself to see if it's evenly worn—if it's smooth and flat, it's likely just a break-in period issue. If all else fails, consider switching to a reputable brand's high-carbon ceramic pads. They might be more expensive, but they're much quieter.

[Sid]

Hey! That sound is all too familiar, like nails on a chalkboard that makes your teeth ache. It's not necessarily a malfunction—it depends on the situation. It's normal to hear it on rainy days or damp roads, as the brake pads absorb moisture and soften slightly. It's also common when starting a cold car in the morning, but the noise usually goes away once things warm up. However, if it screeches like nails scraping metal every single time, I suggest lightly sanding the edges of the brake pads at an angle—it effectively reduces the scraping. Just remember, don’t try to disassemble it yourself; a roadside shop can handle it for around 20 bucks.