SSANGYONG KYRON 2010.01 Manual page 778

13-8
4890-01
3. BRAKE OPERATION AND NOISE
This section describes the noise phenomena possibly occurring 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 Phenomena and Causes
Phenomenon 1. If depressing the brake when the engine is cold, "screeching" sound always
occurs and, after driving for a while, it 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.
Phenomenon 2. Slip or screech after the brake pad replacement.
This usually occurs when the bed-in is not made between the disk 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.
Phenomenon 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.
ESP
KYRON 2010.01