How to Diagnose Brake Noise Issues

October 18, 2023

As a tech, you know one of the most common reasons for customers to visit the shop is brake noise. To them, that’s all it is, noise. But you know there can be many reasons for that sound and many ways to fix it. Let’s talk about some of the most common causes of brake noise.

01. Vibration somewhere in the system

The customer may feel this vibration in the steering column when the brake pedal is depressed, causing a juddering noise and a shake in the steering wheel.

02. Morning sickness – brake noise when they’re cold

It’s when the customer’s brakes produce noise when they’re cold, specifically in the morning when the car starts up for the first time after sitting overnight.

03. Contamination of the friction surface

Brake noise can happen if the physical surface of the friction material has been compromised by too much brake dust.

This can cause uneven braking due to the dust buildup on the surface of the pad, which can be noisy. Rust buildup is also considered an environmental contaminant and rusty rotors can cause squeaking or squealing brakes when the brakes are applied.

How to fix and avoid brake noise in the future
  1. Measure the friction and rotor thickness for the manufacturer’s recommended minimum specifications. If pads or rotors are worn too thin, this can contribute to brake noise as well as unsafe braking overall for that customer.
  2. Check to make sure that calipers are clean and that hardware fits snugly with no gaps. You can use a wire brush to clean the nooks and crannies of the caliper as well as surrounding areas to ensure a dust and rust-free surface.
  3. Proper lubrication is important. Remember, a little lubricant goes a long way. Be sure that all areas are coated in the appropriate lubrication material for the application and that it’s thoroughly dispersed throughout the braking system.
  4. Check on parts that aren’t part of the braking system. This means wheel bearings, steering and chassis components, and the suspension. Sometimes that pesky noise a customer may think is coming from the brakes could actually indicate a serious problem with another part of the vehicle.

While brake noise is a common problem in the shop, you should always be thorough in your inspection of the vehicle first before making a diagnosis. And remember, whether it’s a squeal, a squeak, a grinding sound, or a vibration, not all brake noise is the same and your approach to the repair shouldn’t be either.

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