WHEN SHOULD I REPLACE MY BRAKES
Generally, brake pads need to be replaced after about 50,000 miles. Some need to be replaced after 25,000, while others can last for 70,000 miles, vary depending on where and how you drive, so it goes with the life of brake pads (or brake shoes), the friction material that gets pressed against a metal disc (rotor) or drum to stop your vehicle
The lifespan of a given set of brake pads is dependent on a very wide set of variables ranging from personal driving style to the impersonal laws of physics. Mechanics and manufacturers have a loosely agreed upon mileage range from around 30,000 to 70,000 miles (48,280 to 112,654 kilometers), but stories of pads lasting a mere 100 miles (160.9 kilometers) to an astounding 100,000 miles (160,934 kilometers) abound, as I said ads come in an array of types and compositions -- from composite to metallic to ceramic -- and are attached to an even more bewildering array of brake systems and rotors, all of which affect the life of the pad. Added to the mix are heat, pressure and friction in amounts that would astound most drivers. Indeed the brakes, especially the pads, are some of the hardest working components in your car.
Unfortunately, there is no clear-cut schedule that tells you when it's time to replace the brakes, so you need to rely on your ears and the advice of an experienced automotive technician. Some cars incorporate electronic wear indicators that alert the driver with a dashboard warning if the pads reach minimum thickness.
If the brake pedal pulsates under light or moderate braking, it could reflect wear or a warped disc. If the steering wheel tugs or the car pulls to one side or the other during braking, you may have one worn or otherwise compromised front pad. Other signs when driving are longer stopping distances, or when you apply the brakes your foot goes down farther, closer to the floor, also vibration in the steering wheel, brake or low brake pad warning light is on, brake pads appear too thin.
There are two ways to check for brake wear on disc brakes:
*By looking and by listening. First, check for wear by looking at your brake pads through the spaces between the wheel's spokes. The outside pad will be pressed against a metal rotor. Generally, there should be at least 1/4 inch of pad. If you see less than 1/4 inch of pad, you may want to have your brake pads inspected or replaced.
*Have you ever heard a high-pitched screeching sound when you applied your brakes? That's a small metal shim, called an indicator, which is giving you an audible warning that you need to replace your brake pads. You should be aware of this sound (which is loud enough to be heard while the windows are up, but not necessarily loud enough to be heard over the radio or air conditioner). If you hear it regularly, quickly make an appointment with your mechanic.