Brakes

When it occurs, brake noise may be irritating. However, some sounds are a very normal part of brake operation, while others may indicate a problem. How can you know when noise from your vehicle’s brakes are something to ignore or a problem to investigate?

Know the Answers to Key Questions:

Where does the brake noise seem to originate?
At what speed does the noise occur?
Does it happen when the brakes are cold, or when you have been driving for a while?
Does it happen after many stops, or only after the first few stops?
Does it happen in wet conditions (such as rain, humidity or after a car wash)?

Until recently, asbestos was a common material used in producing brake linings. However, today environmental concerns with asbestos have prompted automobile manufacturers, including Nissan, to significantly reduce the amount of asbestos used in brake products.

For example, Nissan has adopted semi-metallic brake linings that provide excellent brake performance. However, because of the metal-to-metal contact between semi-metallic pads and the brake rotor, these pads may sometimes produce more noise than pads with asbestos linings. As a result, some people may think that the noise they hear indicates a problem with the braking system. To further reduce noise, especially for disc brakes, manufacturers such as Nissan have begun introducing non-asbestos organic (NAO) pads. Nevertheless, a certain amount of noise from brake components is not unusual.

The following are generally considered characteristic of all braking
systems. These noises do not generally indicate any malfunction of the braking system or improper operation, but may as noted below indicate it is time to perform normal brake service.

Loud squeal noise – For disc brake pads with wear indicators, an audible continuous noise is made when the pads need replacement. The wear indicators do not damage the discs, although the pads should be replaced as soon as possible.
Grinding noise – This noise is common primarily during the first few stops on rear drum brakes and on some front disc brakes due to the formation of trace corrosion if the vehicle has not been driven recently. If the noise disappears after a few stops, it does not indicate a problem.
Trace squeak/squeal noise – Front semi-metallic brake linings may emit a soft squeak or squeal noise at medium speeds under light-to-medium pedal force. It also can occasionally occur on rear brakes during the first few stops with cold brakes (especially in the morning), or in conditions of rain or high humidity.
Groan noise – On vehicles equipped with automatic transmissions, a slight groan may be heard when coming to an abrupt stop or when allowing the vehicle to creep forward slowly from a stop.
ABS self-check – If you hear a small click and feel slight brake pedal movement when you reach 3-6 miles per hour after first starting to drive, this is most likely the Anti-lock Braking system properly performing a self-check to ensure that the system is functioning properly.

What Should You Do?

If your vehicle develops brake noise, and you feel unsure about its meaning, you should always take your car in to a qualified technician. Factory trained technicians are best qualified to inspect and offer an accurate diagnosis of specific makes of vehicles.

Some manufacturers offer a choice of genuine factory replacement parts. For instance, all Nissan vehicles are equipped with Nissan Original Equipment (OE) brake pads. They use a non-asbestos organic (NAO) compound that provides state-of-the-art resistance to squeal noise. However, Genuine Nissan Key Value brake pads are also available as a high-quality service replacement part at a lower price for price-sensitive people. These pads use a semi-metallic compound similar to the material in the Nissan OE pads before the introduction of NAO compound pads. Although their braking performance is excellent, some people may experience more brake squeal than they would if using an NAO compound pad. It’s up to you to decide which product better meets your needs.

Now you know what all the noise is about!

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