Mercedes-Benz G-class W463 - Repair manual and operation

10. Brake and auxiliary systems

General information and security measures

General information

The scheme of the organization of a hydraulic actuator of brake mechanisms for three-channel ABS

5.04 — Main and auxiliary vacuum receivers 8.05 — Valve of initial pressure 19. — Supports of the fixed type 19:03 — GTTS 19:05 — Back wheel cylinders	26.03 — Pressure regulator 27.04 — Vacuum amplifier 31.01 — Electronic module of management 31.05 — Hydromodulator 34.02 — Tank of brake fluid

The scheme of the organization of a hydraulic actuator of brake mechanisms for four-channel ABS

5.04 — Main and auxiliary vacuum receivers 8.05 — Valve of initial pressure 19. — Supports of the fixed type 19:03 — GTTS 19:05 — Back wheel cylinders 26.03 — Pressure regulator	27.04 — Vacuum amplifier 31.01 — Electronic module of management 31.05 — Hydromodulator 34.02 — Tank of brake fluid X — the acceleration Sensor

The scheme of an arrangement of the ABS/BAS/4-ETS/ESP components (1 of 4)

A7 — Gidromodulyator ABS K1/2 — the Relay of protection against overloads (petrol models) K1/1 — the Relay of protection against overloads (diesel models)	L6/2 — the Right forward wheel sensor N30 — the Module of management of ABS

The scheme of an arrangement of the ABS/BAS/4-ETS/ESP components (2 of 4)

A7/3 — Gidromodulyator ASR/ETS/ESP A7/3k1 — the Relay Ý/m the valve A7/3k2 — the Relay of the pressure head and returnable pump	K40 — the relay Module (HFM-SFI, HFM-SFI with the air pump, ME-SFI, EDC) N47/7 — the Module of management of ABS

The scheme of an arrangement of the ABS/BAS/4-ETS/ESP components, - three-channel ABS (3 of 4)

A1e17 — the Control lamp of ABS L6/4 — VSS of the right back half shaft	S76 — Switches of blocking of differentials

The scheme of an arrangement of the ABS/BAS/4-ETS/ESP components, - four-channel ABS (4 of 4)

A1 — the Dashboard A1e17 — the Control lamp of ABS L6/3 — VSS of the left back half shaft (is not shown) L6/4 — VSS of the right back half shaft X46 — the Control lamp	S76/1 — the ABS Switch N30/2 — Switches of management of ASD functioning B24 — the acceleration Sensor

Forward and back all models considered in the present manual are equipped with disk brake mechanisms with supports of the fixed type in front and floating type behind.

The brake system consists of the main brake cylinder, the vacuum amplifier and disk brake mechanisms of forward 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 the normal mode, providing adequate braking of the vehicle. In addition pressure valve regulator 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. Liquid pressure in both contours is created by the main brake cylinder (MBC) having a tandem design. Activation of GTTs happens when squeezing a pedal of a foot brake.

The short description of the principles of functioning of auxiliary electronic systems of anti-blocking of brakes (ABS), strengthenings of emergency brake application (BAS), antiprobuksovochny (4-ETS) and antistrange (ESP) is provided in the Part Methods of operation and auxiliary systems.

The tank with brake fluid is fixed on the main thing brake cylinder (MTBC) and hydraulic a path of the brake system supplies with a working body all.

On petrol models the brake amplifier accumulates a part of the vacuum created in the inlet pipeline of the engine. On diesel models in view of lack of such source of depression the special vacuum pump is used. In case of need the special valve provides connection of the relevant source of depression, providing thereby strengthening of the influence developed by a pedal of a foot brake.

The parking brake with the manual drive influences through cables the special shoe assemblies which are a part of disk brake mechanisms of back wheels.

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

PERFORMANCE ORDER

Stop the car, switch off the engine and again start it. Check the level of tension of the rechargeable battery, - if the result of measurement makes less than 10.5 In, make recharge of the battery. If the control lamp of ABS lights up in a start of motion and then after a while dies away, then it indicates the low voltage of the rechargeable battery which increases 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. The car also establish to Poddomkratta it on props, remove wheels and check a condition of an electrical wiring of wheel sensors. More detailed diagnostics has to be carried out in conditions HUNDRED with use of the special equipment for reading of the codes of malfunctions (DTC) which are written down in memory of the module of management.

Security measures

• Brake fluid is among highly toxic and chemically aggressive connections and at contact with body panels destroys a paint and varnish covering!
• The brake dust produced in the course of wear of brake shoes may contain unhealthy asbestos of the person, - at all do not inhale it when cleaning brake mechanisms!
• Work with the 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 along wet roads it is necessary to press periodically a brake pedal for removal of moisture from brake disks;

• In the course of rotation of a wheel moisture under the influence of centrifugal force is dumped from brake disks, but there is a silicone film, rubber attrition products, lubricant and other pollution reducing efficiency of braking!
• After installation of new brake shoes the last have to be earned extra, - try to avoid sharp braking the first 200 km of a 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!
• Burning of dirt to a surface of brake shoes is led to formation of furrows on a surface of brake disks that leads to decrease in efficiency of braking!