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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?
•
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 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 it’s
meaning, you should always take your car in to a qualified technician. Factory trained technicians are best qualified to inspect and offer anaccurate 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!
(Courtesy of the Car Car Council) |
