Mazda 2002 B2300 Owner's Manual page 154

Driving
squeal or groan noises when the brakes are applied. Such noises are
usually heard during the first few brake applications in the morning;
however, they may be heard at any time while braking and can be
aggravated by environmental conditions such as cold, heat, moisture,
road dust, salt or mud. If a "metal-to-metal," "continuous grinding" or
"continuous squeal" sound is present while braking, the brake linings
may be worn-out and should be inspected by an authorized Mazda
dealership.
Four-wheel anti-lock brake system (ABS)
This vehicle is equipped with an anti-lock braking system (ABS), a noise
from the hydraulic pump motor and pulsation in the pedal may be
observed during ABS braking events. Pedal pulsation coupled with noise
while braking under panic conditions or on loose gravel, bumps, wet or
snowy roads is normal and indicates proper functioning of the vehicle's
anti-lock brake system.
NOTE: The ABS performs a self-check after you start the engine and
begin to drive away.
A brief mechanical noise may be heard during this test. This is normal. If
a malfunction is found, the ABS warning light will come on. If the vehicle
has continuous vibration or shudder in the steering wheel while braking,
the vehicle should be inspected by an authorized Mazda dealership.
The ABS operates by detecting the
onset of wheel lockup during brake
applications and compensates for
this tendency. The wheels are
prevented from locking even when
the brakes are firmly applied. The
accompanying illustration depicts
the advantage of an ABS equipped
vehicle (on bottom) to a non-ABS
equipped vehicle (on top) during hard braking with loss of front braking
traction.
WARNING: The Anti-Lock system does not decrease the time
necessary to apply the brakes or always reduce stopping
distance. Always leave enough room between your vehicle and
the vehicle in front of you to stop.
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