What Causes the Squeaking Noise When Starting with Rusty Brake Discs?

[DeVivian]

Here are the reasons for squeaking noises with rusty brake discs: 1. Slight rust on the brake disc surface: It can be removed by continuous braking while driving, and no special treatment is needed because minor rust on the brake discs will be worn off during braking while driving. If the rust is more severe, it may cause vibrations or shaking during braking, such as brake pad vibrations, steering wheel vibrations or shaking, or body vibrations. Of course, this should be done under safe conditions without affecting public traffic. While driving, lightly apply the brakes to let the friction between the brake pads and the brake discs "polish" the surface. 2. Severe rust on the brake discs: When there is significant rust, it can cause unevenness on the brake disc surface, leading to noticeable vibrations in the brake pedal, steering wheel, and body during braking. In such cases, it becomes difficult to remove the rust completely, and even if "polished," it may result in abnormal wear of the brake pads and continued vibrations. Therefore, it is recommended to perform maintenance on the brake discs every two months to prevent severe rust buildup.

[VonLane]

I've encountered this situation while driving too. Brake disc rust mainly occurs due to moisture residue after rainy days or car washing, where the metal surface oxidizes and forms rust in humid weather. When you first start moving, the rotation of the wheels causes the brake pads to rub against the disc surface and remove the rust, which can produce a squeaking sound. This is usually normal, and the sound disappears after driving a few hundred meters. However, if the noise persists every time you start after parking, you should suspect whether the brake pads have worn thin and need replacement. When parking, try to choose dry locations whenever possible, or after washing the car, don't stop immediately—drive a few more laps to evaporate the moisture. In short, don't worry about minor rust, but if it happens repeatedly, carefully inspect the brake system.

[StPaige]

It's really annoying when the brake discs rust and make strange noises when starting, and I'm worried about potential safety hazards. Rust is a natural reaction of metal to moisture, and it's not a big deal if it makes a noise when rubbed off. However, if the rust is too thick or occurs frequently, braking performance may be compromised, affecting emergency stopping distances. It's recommended to try driving short distances for a few minutes to remove the rust first. If the noise becomes more frequent or is accompanied by vibration, take it to a professional shop for a thorough inspection immediately. Don't underestimate the strange noises when starting; regular maintenance of brake components is key, and avoiding parking in water can prevent it. Safe driving is always the top priority.

[IsabelMarie]

This kind of abnormal noise is quite easy to handle. It's caused by the friction of rusted brake discs when starting, which naturally produces sound. I usually lightly tap the brakes a few times in advance to dry the disc surface, or drive a short distance and the noise will disappear. If it still persists, check the brake fluid level or inspect the wheels for any debris. Avoid leaving the car parked outdoors in the rain for extended periods; using a garage or car cover is surprisingly effective for moisture prevention. Simple steps can solve the problem, so don't worry too much.