They may not be something you think about very often, but your vehicle's brakes are one feature that should always be in top working condition. Let's look at how to know when you need new brakes.
Look, listen
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.
One exception is if your car has been sitting after being exposed to water, such as from rain or from washing it. The moisture can cause a thin layer of rust to develop on the brake rotors. This is normal. When you first apply the brakes, the pads pressing on the rust-covered rotors may cause a squeal for a few stops until the rust is worn off and then the sound will disappear.
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