Brakes pads need to be changed out every 30,000 to 75,000 miles. The best way to determine if they’re bad is check with your ears. If you hear noise, it’s time to visit a mechanic. Check for wear by looking at your brake pads.
If you hear a high pitch sound that sounds like metal to metal, this could be sound from your shim. Even though it is soft, you should be able to hear it with your windows rolled up.
Your brakes are not supposed to make noise. 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.
Instead of housing the major components within a metal drum, disc brakes use a slim rotor and small caliper to halt wheel movement. Within the caliper are two brake pads, one on each side of the rotor, that clamp together when the brake pedal is pressed
The disc brake has its own advantages and one of them is easy inspection. The car owner does not have to remove the wheels in order to look at the disc brake system. This brake system also has better stopping power than the drum brake. The disc brakes are completely self-adjusting and because this type of brake is so common there’s a wide selection of disc brake pads from which to choose. There are disc brake conversion kits available for anybody who wants to change over the drum brakes to the more efficient disc system.
Remember to replace your brake pads regularly, you’ll be avoiding damage to your rotors. If you damage your rotors, they will need to be resurfaced.
Here are some other signs of brake problems that you can identify:
Reduced responsiveness or fading. If your brakes are not as responsive as they should be or if the pedal “sinks” toward the floor, this could be an indication of a leak in the braking system. It could be an air leak (in the brake hose) or a brake fluid leak. One telltale sign of a brake fluid leak is the presence of a small puddle of fluid when the car is parked. Brake fluid looks similar to fresh motor oil, but with a less “slimy” texture.
Pulling. If your vehicle pulls to one side, perhaps your brakes are wearing unevenly. Consider taking getting a brake adjustment or draining your fluid.
Grinding or growling. This loud metallic sound means that you have worn down the pads completely. The grinding or growling noise is caused by the two pieces of metal (the disc and the caliper) rubbing together. This can “score,” or scratch your rotors, creating an uneven surface. If this happens, do not be surprised if your mechanic tells you that the rotors need to be “turned” (a process that evens out the rotor surface), or even replaced.
Vibration. A vibration or pulsating brake pedal is often a symptom of warped rotors (but can also indicate that your vehicle is out of alignment). The vibration can feel similar to the feedback in the brake pedal during a panic stop in a vehicle equipped with anti-lock brakes.
It is a sign of warped rotors if the vibration occurs during braking situations when the anti-lock brakes are not engaged. Warped rotors are caused by severe braking for long periods, such as when driving down a steep mountain or when towing. Tremendous amounts of friction are created under these conditions, heating up the rotors and causing them to warp. The vibration is felt because the brake pads are not able to grab the surface evenly. If you drive in these conditions, make sure to stop periodically to allow your brakes to cool off.