2013 SSANGYONG TURISMO Brake system

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(1) Hydraulic Circuit Diagram
When compared to the vehicle equipped with ABS/EBD only, the internal hydraulic circuit has a
normally-open separation valve and a shuttle valve in primary circuit and in secondary circuit.
When the vehicle brakes are not applied during engine running or when applying the non-ABS
operating brakes, the normally-open separation valve and the inlet valve are open, whereas the
normally-closed shuttle valve and the outlet valve are closed.
When the ESP system is operating, the normally-open separation valve will be closed by the solenoid
valve operation and the hydraulic circuit will be established by the shuttle valve. Then, the inlet and
outlet valves will be closed or open depending on the braking pressure RISE, HOLD or DUMP
conditions.

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1. SYSTEM OVERVIEW
When braking suddenly or braking on slippery roads, the vehicle keeps moving forward but the wheels
are locking and not rotating. If these happen, the vehicle may lose stability or rotate resulting in an
accident. ABS helps to maintain directional stability and control of the vehicle. ABS is designed to
secure more safety and increase the control of steering wheel during emergency braking situation.
But, ABS does not guarantee perfect safety beyond its physical limit. ABS in this vehicle contains EBD
function. In normal driving conditions, the brake system operates without ABS function.
1) Basic Theory of ABS Function
To give you a better understanding of the tasks and functions of ABS, we will first look at the physics
principles.
▶Stopping distance
The stopping distance depends on the vehicle weight and initial speed when braking starts. This also
applies for vehicle with ABS, where ABS always tries to set an optimum brake force on each wheel. As
great forces are exerted between the tires and the carriageway when braking, even with ABS the
wheels may scream and rubber is left on the road. With an ABS skid mark one may be able to clearly
recognize the tire profile. The skid mark of an ABS vehicle does not however leave any hint of the
speed of the vehicle in the case of an accident, as it can only be clearly drawn at the start of braking.
▶Brake force on a wheel
The maximum possible brake force on a wheel depends on the wheel load and the adhesion
coefficient between tire and carriageway. With a low adhesion coefficient the brake force, which can be
obtained is very low. You are bound to know the result already from driving on winter roads. With a
high adhesion coefficient on a dry road, the brake force, which can be obtained, is considerably higher.
The brake force, which can be obtained, can be calculated from below formula:

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2) EBD (Electronic Brake Force Distribution) System
▶System description
As an add-on logic to the ABS base algorithm, EBD works in a range in which the intervention
thresholds for ABS control are not reached yet.
EBD ensures that the rear wheels are sensitively monitored for slip with respect to the front axle. If slip
is detected, the inlet valves for the rear wheels are switched to pressure hold to prevent a further
increase in pressure at the rear-wheel breaks, thus electronically reproducing
a pressure-reduction function at the rear-wheel brakes.
ABS features an enhanced algorithm which includes control of the brake force distribution between the
front and rear axles. This is called Electronic Brake Distribution. In an unloading car condition the brake
efficiency is comparable to the conventional system but for a fully loaded vehicle the efficiency of the
EBD system is higher due to the better use of rear axle braking capability.
▶Advantages
Elimination of conventional proportioning valve EBD utilizes the existing rear axle wheel speed
sensor to monitor rear wheel slip.
Based on many variables in algorithm a pressure hold, increase and/or decrease pulsetrain may
be triggered at the rear wheels insuring vehicle stability.
Vehicle approaches the ideal brake force distribution (front to rear).
Constant brake force distribution during vehicle lifetime.
EBD function is monitored via ABS safety logic (conventional proportioning valves are not
monitorable). -
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3) Important Notice
The modulators for production line are not filled with the brake fluid (dry type). But, for after service, they
are filled with the brake fluid (wet type).
Make sure to keep the procedures in service manual when bleeding the air from the brake lines.
Be familiar with the lamp ON conditions to provide the correct information and reliability to customers.
ECU monitors the valve and motor for ABS when the vehicle speed approaches 5 km/h. At this time,
you can hear the clattering noise. 1.
2.
3.

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4. HYDRAULIC CIRCUIT DIAGRAM
1) Hydraulic Circuit of ABS
The vehicle equipped only with the ABS controls the wheel’s braking force using three 3-
channel 4-sensor method. The front wheels that are the primary circuit of the brake system is
composed of two wheel speed sensors and two channel valves system with two inlet valves and two
outlet valves. The rear wheels that are the secondary circuit of the brake system is composed of two
wheel speed sensors, one inlet valve and one outlet valve. This system is similar to the one from the
previous model.

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4. TROUBLESHOOTING
Problem Possible Cause Action
Movements of steering
feels heavyIrregular wear or binding of steering ball joint
due to lack of lubrication or foreign material
insertionLubricate or replace
Damaged or defective steering gear Replace the steering gear
assembly
Incorrect steering pinion preload Adjust
Defective steering shaft join Replace
leakage of steering fluid Repair or replace
Insufficient steering fluid or air insertionFill up fluid or bleed air
Defective steering oil pump Replace
Damaged or loosened pump drive belt
Adjust or replace
Clogging of fluid line Repair or replace
Damaged wheel or tire Repair or replace
Defective suspension Repair or replace
Steering wheel pulls to
one sideDamaged steering linkage Replace
Damaged wheel or tire Repair or replace
Defective brake system Repair or replace
Defective suspension Repair or replace
Excessive free play of
steering wheelWorn steering gear Replace the steering gear
assembly
Worn or damaged steering ball joint Replace
Looseness of steering gear box Retighten
Poor returning of steering
wheelBroken or binding of steering ball joint Replace
Improper correct steering pinion preload Replace the steering gear
assembly
Damaged wheel or tire Repair or replace
Defective suspension Repair or replace