Brake Pads 101: How to Know When They Need Replacing

Image
Words: AutoTrader NZ
Author
Published 9 April 2026

Your brakes are one of the most important safety systems in your car – and brake pads are the part that wears out first. The good news is, your car usually gives you plenty of warning signs before things become dangerous or expensive.

Here’s how to tell when your brake pads need replacing, and what to do next.

1. What Do Brake Pads Actually Do?

Brake pads press against your brake rotors to slow the car down. Over time, friction wears them down – and eventually they need replacing.

Driving with worn pads can lead to:

  • Longer stopping distances
  • Damage to brake rotors
  • Higher repair costs
  • Unsafe driving conditions

2. Common Signs Your Brake Pads Are Worn

Squeaking or squealing

A high-pitched squeal is often the first sign. Many pads have built-in wear indicators designed to make noise when they’re low.

Grinding sound

Grinding usually means the pads are completely worn and metal is rubbing on metal – this can damage rotors fast.

Vibration when braking

If your steering wheel or brake pedal shakes, your rotors may be warped or your pads unevenly worn.

Longer stopping distances

If the car doesn’t stop as sharply as it used to, don’t ignore it.

Brake warning light

Some vehicles have sensors that alert you when pads are low.

3. How Long Do Brake Pads Last?

Most brake pads last around 30,000–70,000 km, depending on:

  • City vs motorway driving
  • Driving style
  • Vehicle weight (SUVs wear faster)
  • Towing or heavy loads

4. Quick DIY Check

You can sometimes see the brake pad thickness through the wheel spokes.

As a general rule:

  • More than 5mm = healthy
  • 3–4mm = getting low
  • Under 3mm = replace soon

👉🏼 Top tip: If you’re unsure, a mechanic can check them quickly during a WOF or service.

Bottom Line

Brake pads wear out gradually, but replacing them early keeps your car safe and helps avoid bigger repair bills later.

If you notice squeaking, grinding, or reduced braking performance, it’s worth getting them checked sooner rather than later.

👉🏼 Stay safe and keep your car road-ready.