Brake Pads & Rotors: How to Know When to Replace Them

BY Erin C.

As an aspiring or professional at-home mechanic, replacing your brakes is one of the first tasks you’ll take on after mastering the oil change. With several moving parts – the brake rotors, brake pads, calipers and more – it’s important to know what’s causing the problem and what needs to be done before you get started. When time and mileage take their toll on your brake system, watch out for these simple-to-spot signals to know just what needs to be done to keep your vehicle operating – and stopping – at its best.

Noisy Brakes

The most common symptom associated with brake wear is noise. When your rotors become warped or badly worn, they won’t lie completely flat which creates a squealing or squeaking sound as the pad quickly oscillates against the rotor.. Worn brake pads can also be to blame for that skin-crawling squeal thanks to accumulated dust or most commonly a wear sensor which is intentionally designed to come into contact with the rotor, creating a loud screeching noise every time the brakes are applied, indicating it’s time for new pads.

Vibrations or Pulsating Pedal

Another clear indication that your brake pads and/or rotors have gone bad is excessive vibration or pulsation. Warped or worn rotors provide irregular contact that will cause vibrations that can be felt through your brake pedal. Brake pad deposits can also cause a pulsating brake pedal, the result of deposited pad material embedded in to various sections of the rotor surface.. This symptom will not only affect stopping power, but can also cause pulling and other dangerous handling issues. If caught early enough, a resurfacing a rotor can sometimes cure the issue, but often times this will just delay the problem, and the rotor will need to be replaced anyway.

Poor Brake Response

Brake fade is a term used to describe when your brake pads and rotors no longer generate sufficient friction to stop your vehicle safely. It also can be the result of your brake fluid boiling from heat. These air pockets cause a loss in hydraulic power transferred to your brakes. If your brake pad is insufficient for application, either from being excessively worn or overheated, it will severely reduce your brake response. It is equally important to pay attention to these physical signs, along with the above audible symptoms in order to maintain a safe and secure vehicle for you and your passengers. Brake fluid plays an equally critical part of a well functioning brake system. The older the fluid gets, the more prone to absorbing moisture it gets which leads to reduced braking effectiveness and heat resistance.

Grooves or Score Marks

Thankfully, most of the signs that indicate failing brake pads and rotors are easy to identify. By performing a simple visual inspection, you’ll be able to spot another symptom of failing rotors – scoring or inconsistent grooves on the face of the rotor. These scoring marks or grooves develop on your rotors from repeated contact with the brake pads, taking away from their capacity to slow your vehicle.