How do you know when to change your brake pads?

Answer 1

If you hear a grinding sound when you hit the brakes you probably need new brake pads. Good chance you will also need new rotors.

Take the tire(s) off and look at the pads. If the metal part is about to touch the rotor you need new pads. Let it go a little longer and you may need new rotors.

Some pads have a small metal tab that will touch the rotor when you need new pads. It will cause a squealing noise when you hit the breaks. When you hear the squeal you need to replace the pads. If you ignore the squeal long enough you may also need new rotors

Normally you have a early warning system on most vechicules that is simple when your car is in motion and the brake pedal is not depressed you will hear a squeaking sound which gives you a warning that it is time for the wallet to be opened.