Brake Operation And Noise - SSANGYONG Kyron Repair Manual

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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.
ABS/ESP SYSTEM
KYRON SM - 2005.09
CHANGED BY
EFFECTIVE DATE
AFFECTED VIN