It's incredibly important that you occasionally check your brake pads for wear and tear. Worn brake pads are unsafe and prevent your car from coming to a quick halt. Those living in an urban environment will have to replace their pads more often than those in rural areas. If you notice symptoms of worn brake pads, you can do a rough estimate with a straw, or you can do a more precise measurement by taking off the wheel. If you notice that your brake pads are worn down, you should replace them as soon as you can.

      Listen to your brakes as you come to a stop. Many brakes have squealers installed on them which will indicate when your brake pads start to wear thin. These squealers will let out a loud, high-pitched sound when your         brake pads get too thin.

• You can see if your brakes have squealers by taking off the wheel. It will be a small tab of metal next to your pads.                                                
  2
  Feel your brakes as you come to a stop. If you push the brake down to the floor but your car doesn’t come to an immediate stop, your brake pads might be worn down.
    
  3

  Check for a pulsating or vibrating brake pedal. A pulsating or vibrating brake pedal may mean your rotors are warped. A mechanic will be able to better evaluate the issue。

  4
  Determine whether your car pulls to one side when you stop. Pulling to one side as you come to a stop is an indication that one side of the brakes are more worn than the other side. If you notice your car pulling to one side when you press the brake pedal, check that side's front tire and make sure that the brake pad isn't worn down.
  5
  Get a professional to inspect your rear brakes. Some older cars and rear brake systems may have brake shoes instead of pads. These are cylindrical metal rings that fit around your wheel's rotors. If you suspect that your brake shoes are bad, you should take your car to a mechanic so that they can inspect them.

  • The exterior "braking material" (usually made of metal) should measure the same thickness on both sides. You can take measurements of the material with a ruler.
  • Rear brake shoes are good for 30,000–40,000 miles (48,000–64,000 km) and can last twice as long as your front brakes.