08-94411-01
Under View (4WD, Automatic Transmission)
Rear suspension
1. SUSPENSION
The suspension is the device to connect the axle and vehicle. It absorbs the vibrations and impacts from
road surface, which enhances the comforts, driving force, braking force and drivability.
Front suspension
09-10
This section describes the noise phenomena occurred possibly in the brake system operation.
Distinguish between the information given below and the actual problems and then, inspect the vehicle
and take appropriate measures.
Noise symptoms and Causes -
Symptom 1. If depressing the brake pedal when the engine is cold, "screeching" sound always
occurs and, after driving for a while, the sound disappears..
This usually occurs in the morning. When the temperature goes down, the dew condensation
phenomenon sets moisture on the brake disc as the window frost forms. Due to this moisture, the iron
within the brake disc and pad oxidizes, forming undetectable micro-rusts on the disc surface. When
starting the engine under this condition, noise may sound due to the friction of micro-rusts. When
operating the brake several times, the disc temperature goes up and the micro-rusts come off and the
noise goes away. Depending on the driving conditions, noise gets louder when slightly depressing the
brake pedal and oppositely, noise is smaller when deeply depressing the brake pedal. This is simply a
physical phenomenon, called "morning effect" in professional terms, and does not imply any problems
with the brake system.
Symptom 2. Slip or screech after the brake pad replacement.
This usually occurs when the bed-in is not made between the disc and the pad's friction material. The
bed-in is a state that the brake system normally works and gives no noise out, when, after about 300 km
city driving, the contact area of the pad friction material is enlarged and the disk is in complete contact
with the pad's friction material. Therefore, for some time after the brake disk/pad replacement, the brake
system poorly operates or noise (abnormal sound) occurs due to the partial contact.
Symptom 3. "Groaning" sound occurs in the automatic transmission vehicle when slightly taking the foot
off the brake pedal to slowly start after waiting for the signal, or slightly depressing the brake pedal.
This is the noise "Creep groan" that occurs when, in both the automatic and manual transmission,
slightly releasing the brake pedal in the neutral gear at downhill roads.
It frequently occurs at the low braking power and low speed, through the following process. When
operating the brake system at low speed and low pressure, adhesion and slip repeatedly take place
between the brake disk and the friction material, and this makes the braking power inconstant, instantly
increasing or decreasing, and gives out the brake noise.
It is also a physical phenomenon and has no relation with the brake performance.BRAKE OPERATION AND NOISE ▶
