E39 series BMW 5

since 1996-2001 of release

Repair and car operation

Brake system

Specifications

Separate characteristics are provided also in the text of Head and in case of obligation of their performance are allocated with a bold print

Design

Disk on all wheels. Additional drums of the parking brake on back wheels
The brake amplifier at cars with the petrol engine.
Double-circuit hydrosystem: one contour of the forward brakes, the second - back.
Distribution of effort of braking is carried out by anti-blocking system (ABS)

Characteristic	Value
Type of brake liquid	DOT 4
Blocks of a disk brake: the minimum thickness without a back plate	3.0 mm
Blocks of a drum-type brake: minimum thickness	1.5 mm
Brake disk forward:
• minimum thickness	20.4 mm
• diameter	296.0 mm
Brake disk back: minimum thickness
• continuous disk	8.4 mm
• a ventilated disk	18.4 mm
• diameter	298.0 mm
Amount of processing and admissions:
• the maximum size of processing on the party	0.8 mm
• the admission for the thickness	0.02 mm
• maximum face palpation •• the established •• the removed	0.2 mm 0.05 mm
Parking brake:
• diameter of a brake drum	185.0 mm
• maximum radial palpation	0.1 mm

Efforts of a tightening of carving connections

The moments of an inhaling of fixture are given in the text of Head and on some иллюстрациях*.
*vydelenny in the text a bold print the moments of an inhaling are subject to exact observance; the efforts not allocated with a bold print are given only roughly.

General information

The brake system consists of the main brake cylinder, the amplifier of a brake and disk brakes of lobbies and back wheels. The hydrosystem of brakes has two contours: one contour influences the forward brakes, the second on the back. It provides possibility of braking of the car in case of failure of one of contours, for example owing to system depressurization, thanks to action of another. Pressure of brake liquid is created in the dual main brake cylinder as a result of pressing of a pedal of a brake. The regulator of brake effort in system is absent, since distribution of effort of braking is carried out by anti-blocking system (ABS).

The tank of brake liquid is in an impellent compartment on the left side under the case of the filter of clean air. The tank supplies system of braking with liquid.

The vacuum amplifier of a brake at cars with the petrol engine accumulates a part of air soaked up by the engine. The effort of a pedal of a brake via the valve amplifies at the expense of available vacuum. At the diesel engine of vacuum on absorption is not present. Therefore here the vacuum for strengthening of braking is created by the vacuum pump located on a head of cylinders.

All disk brakes are equipped with rigid supports. When braking brake shoes nestle on a disk the piston.

Supports are made of an alloy of light metal. It provides the good heat removal, being formed in the course of braking that interferes with emergence of so-called "feding". “Фединг” represents easing of efficiency of braking owing to strong heating of brakes.

On left forward and right back brakes sensors of wear of brake shoes are established.

The parking brake influences back wheels and is actuated through a cable. As the disk brake as the lay has certain shortcomings, on back wheels two drum-type brakes which have been built in brake disks are in addition established. The drive of the parking brake is carried out from the lever.

When cleaning brake system the brake dust is formed. This dust represents health hazard. Therefore when cleaning brake system watch that the brake dust did not get to respiratory ways.

Brake shoes are object of control from bodies of technical supervision. Besides, they are intended for use in concrete model of the car. It is recommended to apply original brake shoes.

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.

It is necessary to hand over the fulfilled brake liquid in special point of utilization. To throw out it with other household waste it is not allowed.

At movement on wet roads it is necessary to press periodically a brake pedal for drying of disk brakes. In the course of wheel rotation moisture under the influence of centrifugal force is dumped from brake disks, but there is a film of silicone, a product of an istiraniye of rubber, greasing and the other pollution reducing efficiency of operation of brakes.