In the braking system, brake pads are the component that applies pressure and creates friction to the brake rotors, and this stops the wheels.  Think of the number of times this action takes place on a daily, weekly, monthly and annual basis – and it’s no surprise that brake pads suffer wear and tear, and usually need replacing regularly.
There are no hard and fast rules on this. It will differ vehicle to vehicle and vary by the way you drive, where you drive and how often you drive. The typical lifespan for a set of brake pads is 50,000 – 80,000 kms, depending on the quality of brake pad you have installed.
Loud squealing

If you hear a squealing sound while braking that is one warning sign that your brake pads need replacement. If hear a grinding noise, it’s likely the brake pads have been worn down completely.

Visual check

It’s possible to look at brake pads too and identify wear and tear. Pads should be visible by looking through the spokes of the car’s wheel – the outside pad is pressed against a metal rotor.

There should be at least 3 mms of the pad visible. If you see anything less, get the brake pads inspected.

Pulling to one side

While driving, if the vehicle feels as if it’s pulling to one side or the other, then it’s also likely that the brake pads need to be changed.

Bad vibrations

If the brake pedal vibrates when you push your foot down on it, they could be warped due to heat.