Mercedes M-Class W163

since 1997 of release

Repair and car operation



Mercedes W163
+ Mercedes-Benz Cars of a class M (W163)
+ Governing bodies and receptions of safe operation
+ Current leaving and service
+ Engine
+ Systems of cooling, heating and air conditioner
+ the Power supply system and production of the fulfilled gases
+ Systems of electric equipment of the engine
+ Manual box of gear shifting
+ Avtomaticheckaya transmission
+ Transmission line
- Brake and auxiliary systems
   General information and security measures
   Check of brake system on leaks
   Check of serviceability of functioning of the vacuum amplifier of brakes
   Check of the transient valve
   Removal and installation of the main brake cylinder
   Removal and installation of the vacuum amplifier of brakes and sensor of a course of a diaphragm of BAS
   Removal and ETS/ESP hydromodulator installation
   Removal and installation of the hydraulic lines laid between GTTs and the ETS/ESP hydromodulator
   Assessment of degree of wear and replacement of brake shoes
   Replacement of brake hoses
   Removal and support installation
   Removal and installation of a brake disk
   Replacement of boots of the parking brake
   Pumping of brake system
   Removal and installation of pedal knot and sensor switch of stoplights
   Removal and installation of a pedal of raising of the parking brake
   Removal and installation of hummock assembly of a drive of the parking brake
   Adjustment of a drive of the parking brake
   Removal and installation of wheel ABS/ETS/ESP sensors
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment


General information and security measures

General information

The brake system consists of the main brake cylinder, the vacuum amplifier and disk brake mechanisms of lobbies and back wheels and is divided according to the diagonal scheme into two independent hydraulic contours. At refusal of any of contours (for example as a result of sealing violation) the second continues to function in a normal mode, providing adequate braking of a vehicle. In addition the valve regulator of pressure providing dynamic correction of effort of braking of back wheels according to change of load of a back axis of the car is built in contours of both back brake mechanisms. Pressure of liquid in both contours is created by the main brake cylinder (GTTs) having a tandemny design. Activation of GTTs occurs when squeezing a pedal of a foot brake.

Scheme of the organization of a hydraulic actuator of brake mechanisms

1 — ГТЦ
5а — the Support of the right forward brake mechanism
5b — the Support of the left forward brake mechanism

6а — the Support of the right back brake mechanism
6b — the Support of the left back brake mechanism
A7/3 — Gidromodulyator of auxiliary systems

The short description of principles of functioning of auxiliary electronic systems of anti-blocking of brakes (ABS), strengthenings of emergency braking (BAS), distribution of brake efforts (EBV), is provided by antiprobuksovochny (ASR/4-ETS) and protivozanosny (ESP) in Head Governing bodies and receptions of safe operation.

Scheme of an arrangement of components of system of strengthening of emergency braking (BAS)

1 — ГТЦ
2 — the Vacuum socket
А1е17 — the Control lamp of ABS
А1е48 — the Control lamp of BAS/ASR
A7/7 — the Vacuum amplifier of brakes

A7/7b1 — the Sensor of a course of a diaphragm of BAS
A7/7s1 — the Sensor switch of an otpuskaniye of BAS
A7/7y1 — Ø/m the BAS valve
N48 — the Module of management BAS integrated into the module of management of ESP (N47-5)
Y61 — the GTTs Valve switch (if it is provided)

Scheme of an arrangement of components of auxiliary electronic systems ASR/ETS/ESP

А1е17 — the Control lamp of ABS
А1е35 — the Control lamp of ETS
А1е36 — the Light indicator 4-ETS
A7/3 — Gidromodulyator
F1 — the Assembly block of safety locks and the relay
k25 — the Relay of the pressure head and returnable pump
L6/1 — the Left forward wheel sensor
L6/2 — the Right forward wheel sensor

L6/3 — the Left back wheel sensor
L6/4 — the Right back wheel sensor
N47-5 — the Module of management of BAS/ESP
S9/1 — the 4-contact sensor switch of stoplights
S12 — the Sensor switch of raising of the parking brake
S11 — the Sensor switch of level of brake liquid
X11/4 — the Diagnostic DLC socket of system of onboard self-diagnostics

The tank with brake liquid is under the main brake cylinder, it supplies with liquid all hydrosystem of braking.

The amplifier of a brake accumulates a part of the vacuum created in the soaked-up pipeline of the engine. As the diesel engine has no necessary vacuum on absorption, cars with the diesel engine have the special vacuum pump. By means of the corresponding valve if necessary the effort to pedals of a brake increases thanks to vacuum action.

The parking brake with a pedal drive influences through cables brake mechanisms of back wheels. In addition back brake mechanisms are equipped with drum-type knots of the parking brake with pedal тросовым a drive.

Principles of functioning of auxiliary systems ABS/4-ETS/ESP/EBV

The electrohydraulic scheme of functioning of auxiliary systems is presented on an illustration which all references meeting in the text concern.

Scheme of a hydraulic contour of auxiliary electronic systems ABS/4-ETS/ESP/EBV

4 — the Operating knot of a brake path
5а — the Support of the right forward brake mechanism
5b — the Support of the left forward brake mechanism
6а — the Support of the right back brake mechanism
6b — the Support of the left back brake mechanism
7 — the Control valve
9 — the One-pass control valve of the returnable pump
10 — the Damper with operating plate
11 — the Low-pressure head accumulator
A7/3 — Gidromodulyator of auxiliary brake systems
m1 — the Pressure head and returnable pump
p1 — the being self-filled pump of first (DK) of a diagonal contour
p2 — the being self-filled pump of second (SK) of a diagonal contour
y6 — Left forward Ý/m the valve of deduction of pressure (inlet)
y7 — Left forward Ý/m the valve of dumping of pressure (final)
y8 — Right forward Ý/m the valve of deduction of pressure (inlet)

y9 — Right forward Ý/m the valve of dumping of pressure (final)
y10 — Left back Ý/m the valve of deduction of pressure (inlet)
y11 — Left back Ý/m the valve of dumping of pressure (final)
y12 — Right back Ý/m the valve of deduction of pressure (inlet)
y13 — Right back Ý/m the valve of dumping of pressure (final)
y24 — the Managing director multiple-pass Ý/m the valve of first (DK) of a diagonal contour
y25 — the Managing director multiple-pass Ý/m the valve of second (SK) of a diagonal contour
y26 — Ø/m the valve of preliminary filling of first (DK) of a diagonal contour
y27 — Ø/m the valve of preliminary filling of second (SK) of a diagonal contour
DK — the First diagonal contour
SK — the Second diagonal contour
VL — the Left forward wheel
VR — the Right forward wheel
HL — the Left back wheel
HR — the Right back wheel

The structure of the hydromodulator of auxiliary brake systems (A7/3) includes components of systems of the closed contour of dynamic control of ABS systems, 4-ETS/ASR and ESP.

Pressure head and returnable pump (A7/3m1)

Being self-filled pressure head and returnable pumps (p1, p2) are built in assembly of the hydromodulator (A7/3) and are switched by pulse signals in phases of forcing and dumping of pressure of system of active management of ETS and ESP, and also during adjustment of a returnable stream at ABS activation.

Being self-filled pressure head and returnable pumps (p1, p2) are started if necessary for the purpose of noise level minimization.

Each brake contour is equipped with the separate damper (10) reducing level of noise made by the pump.

Electromagnetic valves of deduction (inlet) and dumping (final) pressure (A7/3y6 - A7/3y13)

One 2/2-hodovy valve is used at management of pressure in contours of each of wheels in phases of forcing/deduction and deduction/dumping of the operating ABS, ETS and ESP modes.

Low-pressure head accumulator (11)

The low-pressure head accumulator (11) is filled with brake liquid in a phase of dumping of pressure of ABS, ETS or ESP and provides its transfer to pressure head returnable pump (p1/p2).

Operating multiple-pass electromagnetic valves (A7/3y24 and A7/3y25)

Electromagnetic multiple-pass valves switches (and y25) provide with y24 an otsechka of active pressure head diagonal contours from GTTs during ETS and ESP functioning. Also valves provide pressure dumping when lifting it over 150 atm. Brake liquid passed through valves switches goes back to GTTs.

Electromagnetic valves of preliminary filling (A7/3y26 and A7/3y27)

Valves (y26, y27) open in phases of increase of pressure of ETS/ESP.

Principle of functioning of assembly of the sensor of the withdrawing moment / cross-section overloads of ESP

Sensors of the withdrawing moment and cross-section overloads with a view of economy of a place are incorporated in uniform assembly (B24/2). Micromechanical touch assembly will transform cross-section and vertical projections of angular accelerations to electric signals. Various on weight working elements under the influence of arising during not inertial movement of a vehicle (commission of turns and accelerations) overloads provide various extent of deformation. The special electronic converter converts received signals and on the tire CAN transfers them to the module of management of antiprobuksovochny and protivozanosny systems (N47).

The sensitive element of the sensor of the withdrawing moment is created from a micromechanical ring (and), equipped with eight spring crossing points (b) providing its movement and electromagnetic action. At rotation in assembly arise additional кориолисовы the forces proportional to speed of rotation, fixed in an electromagnetic way and, after transformation in the ACIS module in a form of the analog signals, combinations of devices given out on the control unit.

Design of the capacitor sensor of the withdrawing moment of ESP system

and — the Silicon ring
b — the Spring crossing point

c — the Electronic sensor

The principle of measurement of cross-section overloads is based on use of a spring and mass element with the capacitor detector. Working tension moves from the module of management of ESP (N47-2).

Arising during commission of turns cross-section overloads provide shift of a spring and mass element from position of balance on the size proportional to value of arising force of reaction. Any change in the provision of an element leads to change of capacity of the detector. Further, the fixed size of a deviation will be transformed to the alarm tension allowing the module of management of ESP (N47-2) to make a quantitative assessment of sizes of fixed cross-section overloads.

The electronic module of management watches that the system, in case of mechanical damages of a contour (for example, cable break), or at excessive power failure, was automatically disconnected. The situation is displayed on the dashboard by activation of a control lamp of ABS. At the same time there is a shutdown of ESP and BAS systems that proves to be true operation of the corresponding indicator (see. Head Governing bodies and receptions of safe operation). The main brake system continues keeps thus the working capacity, - during braking the car behaves as if the ABS system is absent.

Activation during movement of a control lamp of ESP testifies to detection of malfunction of the amplifier of emergency braking (BAS) or protivozanosny system (ESP), - the relevant systems thus also are disconnected with preservation of ability of functioning of the main brake system.

At activation during movement of a red control lamp of brake system, it is necessary immediately to stop and try to establish to find out a cause of infringement falling of level of brake liquid, or not up to the end released lever of the parking brake can appear which in particular.

Operations procedure at operation of a control lamp of ABS during movement

Stop the car, switch off the engine and again start it.

Check level of tension of the storage battery, - if the result of measurement makes less than 10.5 In, make battery additional charge.

If the control lamp of ABS lights up in a start of motion and then after a while dies away, it indicates a low voltage of the storage battery which raises after the beginning of operation of the generator.

Make sure of reliability of fastening of tips of wires on polar plugs of the battery, in case of need tighten fixture.

To Poddomkratta the car also establish it on props, remove wheels and check a condition of electroconducting of wheel sensors.

More detailed diagnostics should be carried out in conditions HUNDRED with use of the special equipment for reading written down in memory of the module of management of codes of malfunctions (DTC).

Security measures

  • Brake liquid is among highly toxic and chemically aggressive connections and at contact to body panels destroys a paint and varnish covering!
  • The brake dust developed in the course of wear process of brake shoes can contain unhealthy the person asbestos, - at all do not inhale it when cleaning brake mechanisms!
  • Work with brake system demands special purity and exact observance of instructions. In the absence of necessary experience it is expedient to address on HUNDRED.

At movement on wet roads it is necessary to press periodically a brake pedal for moisture removal from brake disks

  • In the course of wheel rotation moisture under the influence of centrifugal force is dumped from brake disks, but there is a silicone film, products of an istiraniye of rubber, greasing and the other pollution reducing efficiency of braking!
  • After installation of new brake shoes the last should be earned extra, - try to avoid sharp braking the first 200 km of run after replacement performance!
  • The disk brake mechanisms damaged by corrosion when braking create the effect of jolting which is not disappearing over time, - replace disks!
  • Dirt burning to a surface of brake shoes lead to formation of furrows on a surface of brake disks that leads to decrease in efficiency of braking!