E46 series BMW 3

since 1998 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

General parameters
Design	Disk brake mechanisms on lobbies and back wheels. Disks of forward brake mechanisms - ventilated. Disks of back brake mechanisms - ventilated except models 316i and 318i. Electronic and hydraulic system of anti-blocking of brakes of ABS. The braking monitoring system on CBC turns. Hydraulic system - double-circuit, diagonal. Drum-type mechanisms of the parking brake on the back wheels, equipped with a hummock drive
System of anti-blocking of brakes of ABS	dynamic system of stabilization of stability built in ABS DSC3 on the early E46 models antiprobuksovochny system (Teves ABS/ASC Mark20ET)
Thickness of overlays of brake shoes of disk brake mechanisms
wear limit (without a back plate)	3 mm
Thickness of overlays of brake shoes of drum-type brake mechanisms
wear limit	1.5 mm
Brake mechanisms of forward wheels
Minimum admissible thickness of a brake disk	20.4 mm
Diameter of a brake disk
316i, 318i, 320d, 320i, 323i	286 mm
328i, 330d	300 mm
Brake mechanisms of back wheels
Minimum admissible thickness of a brake disk
316i, 318i,	8.4 mm
320d, 320i, 323i, 328i, 330d	17.4 mm
Diameter of a brake disk
316i, 318i	280 mm
320d, 320i, 323i	276 mm
328i, 330d	294 mm
Admissions of the sizes and palpation of brake disks:
the maximum amount of processing on the party	0.8 mm
admission of thickness of a brake disk	0.01 mm
maximum lateral palpation
it is established	0.2 mm
it is removed	0.04 mm
Parking brake:
diameter of a brake drum	160.0 mm
maximum radial palpation of a brake surface	0.1 mm
Brake liquid	1.5 l of DOT 4 of the FMVSS 116 specification
Efforts of a tightening of carving connections
The moments of an inhaling of fixture are given also 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
Directing bolts of a brake support of forward wheels	28 N • m
Mudguard, ahead	10 N • m
The lever of the parking brake on a body floor	25 N • m
Brake hose on a support	235 N • m
Bolts of wheels	120 N • m

The brake system consists of the main brake cylinder, the amplifier of a brake and disk brakes of lobbies and back wheels. The brake hydrosystem has two contours: one contour influences forward wheels, another on the back. Thanks to it at refusal of one of contours braking of the car is carried out by other contour. Pressure of liquid in brake system is created in the dual main brake cylinder by pressing a brake pedal.

The tank with brake liquid is located in an impellent compartment on the left side over the main brake cylinder. It provides with liquid all brake system. The amplifier of a brake at the block of cylinders accumulates a part of the vacuum created by the engine at absorption. Via the valve the effort of a pedal of a brake if necessary amplifies vacuum. As the diesel engine has not enough the vacuum created at absorption, the vacuum is created by the special vacuum pump located on a head of cylinders.

Disk brakes are equipped with supports with one cylinder.

The parking brake is actuated through hummock drafts and influences back wheels. As the disk brake is inefficient as lay, on back wheels there are in addition two drum-type brakes which have been built in brake disks. Drum-type brakes are put in action only via the lever of the parking brake.

Work with brake system demands special purity and an order. If necessary experience of such work is absent, she should be seen off on HUNDRED. It is recommended to apply the brake shoes resolved by the manufacturer of the car. At movement on wet roads it is necessary to press periodically brakes to dump from brake disks a precipitation. At the expense of the centrifugal force arising at rotation of wheels, water is removed from brake disks. However on disks there is a thin film of silicone, greasing and pollution which reduce efficiency of action of brakes. On brake shoes and rain flutes lead dirt to education задиров on a surface of brake disks. All this promotes decrease in efficiency of braking. When cleaning brake system the brake dust is formed. This dust is unhealthy. Therefore when cleaning brake system, watch to inhaling a brake dust.

Systems of stabilization of stability of the car on ABS/CBC/ASC Road + T/MSR/DSC

ABS: The anti-blocking system interferes with blocking of wheels at sharp braking of the car. Thanks to it even during braking the car remains operated.

Continuation of ABS is the braking monitoring system on turns of SVS (Cornering Brake Control). SVS on signals of four ABS sensors learns that the car moves on turn. If braking occurs on turn, it usually leads to that the car tries, as though to be screwed in turn. This effect is a consequence of increasing load of a forward axis. The braking monitoring system on turns of SVS regulates increase of brake effort in such a manner that it accrues quicker on external in relation to turn a forward wheel, than on other wheels. Thus, action, the return to the effect specified above is created. SVS works at turns practically as system of electronic distribution of effort. Thanks to it there is possible an impact on back wheels with big brake effort.

ASC (system of automatic stabilization) reduces a torque of both driving wheels by engine capacity reduction when wheels at dispersal of the car start to be turned.

In the presence of the effort monitoring system coupling (+Т) at a car troganiye from a place being turned wheels are braked. As a result of it the torque is switched to "being linked" wheels. The considered system practically operates as electronic blocked differential which is disconnected at speed over 40 km/h. ASC system use + in T is displayed to the driver by fire of a control lamp.
+ the T is integrated into ASC system system of regulation of the traction moment of MSR. This system interferes with blocking of driving wheels on the equal road at the expense of brake operation of the engine when switching on lower transfer or at gas reduction.

At car movement with snow chains in deep snow or at a troganiye from a place from deep dirt it is expedient to disconnect ASC system + T by means of the switch on the central console. At repeated turning on of the specified switch or at the following start of the engine ASC system + the T again automatically joins.

The system of dynamic control of stabilization of DSC is established as the additional equipment on model 328 i. The monitor of DSC system carries constantly out comparison of the current parameters of movement with the parameters of a perfect condition received by a settlement way. If, for example, the car at movement on turn it is too strong недоуправляется, the capacity of the car and, therefore, speed of movement decrease, at the same time the system brakes a back wheel, internal in relation to turn. Thanks to it the turned forward wheels create more lateral direction and the car does not leave turn.

Instructions on ABS/CBC/ASC systems + T/MSR/DSC

The safety scheme in the electronic control unit watches that in the presence of defect, for example, cable break, or at too low voltage of the storage battery (below 10 In) the system was disconnected. At normal work after ignition inclusion the control lamp lights up for short time and then dies away. If the lamp does not die away and in the course of movement continuously lights up, it indicates malfunction existence. The car can be maintained further, but the system of electronic regulation is disconnected.

If in the course of movement one or several control lamps on a control panel light up, pay attention to the following:

1 Stop the car for short time, switch off the engine and again start it.
2 Check tension of the storage battery. If it less than 10.5 In, charge the battery.

If in a start of motion control lamps light up, and then through short time die away, it specifies that in a start of motion tension of the storage battery was low, then during movement the battery was charged from the generator.

3 Check, whether plugs of the storage battery are tightened and whether there is a reliable contact.
4 Lift and establish the car on supports. Remove wheels, check external survey existence of damages of wires of sensors of number of turns of wheels (existence of retyrannies). More careful check of ABS/CBC/ASC system + should be carried out T/MSR/DSC by means of special devices. Address to the Section Diagnostics of malfunctions. Work it is desirable to lead HUNDRED in conditions.

Before carrying out electrowelding works it is necessary расстыковать the socket of an electronic monitor. Undocking should be made only at the switched-off ignition. At carrying out painting works it is authorized to subject a monitor to short-term influence of temperature to +95°С, and it is long-term (no more than the 2nd hour) – to temperature +85°С.