When it comes to cars, the brakes can be one of the noisier parts of a vehicle - especially when they're not working correctly. When a driver hears grinding or squealing coming from their brakes, their first reaction might be to panic because it sounds like something is seriously wrong. However, drivers should take it easy and be comforted by the fact that brakes are actually designed to make noise when they begin to wear out. This lets the owner know it's time for brake service.
Hearing "there's a problem with your brakes" might cause some drivers' hearts to skip a beat. This isn't a movie, however. Your brakes are most likely not going to suddenly give out and send you careening down the street without the ability to stop. Typically, there are plenty of noises you'd have to ignore for a very long time before major problems will arise with your brakes.
The most common noise that drivers report is squealing, or any kind of high-pitched whine. This is related to a vehicle's brake pads, which prevent metal-on-metal grinding from occurring. It's important for drivers to keep in mind that some brake pads, especially on modern front-wheel drive vehicles, are semi-metallic themselves. Thus, it's not uncommon to hear a squealing noise with these brakes, even if the pads were just recently changed. In fact, the higher-end brake pads you buy, the more likely you are to get some noise coming from them.
Yet the occasional squeak or squeal when you stop will be different from what happens when the brake pads begin to wear down. Brake pads are designed to include certain "wear indicators" that are actually underneath the surface of the pads. The indicators coming into contact with the metal brakes are what make the squealing noise. So, this is very much by design and is a sign that you should bring your car in for brake service or replace the pads yourself. The vehicle's brake light may also come on.
It's important for drivers to take care of their brakes soon after they begin hearing the squealing noise, because if they don't it could ultimately lead to bigger problems. Another common noise many drivers encounter is a grinding, metal-on-metal sound. This is exactly what it sounds like - the brake lining has worn off to the point that the rotors are now directly rubbing against the metal. As you can probably tell from the sound, this is bad. In most cases, the driver will feel the vibration when they go to brake, and they may also notice their car pulling to one side when they slow down.
This is why changing the brake pads is so important. Buying new brake pads is cheap, and replacing them is simple. Buying new pads, rotors and possibly brake drums because you've let the issue get so bad the parts are scraping together will be significantly more expensive.
There are other noises drivers should watch out for as well, though they are decidedly less common. Clicking can occur with disc brakes, and has to do with how the caliper fits over the brake. Normally, clicking indicates a spring between the caliper and brake has become broken, which will need to be fix.
It's also possible drivers might encounter a loud clunking noise when they brake. This actually doesn't have to do with the brake at all, and is probably tied to one or more steering or suspension components wearing out.