Remove/install brake booster

AR43.10-D-0350TSF

Remove/install brake booster

27.11.2019

Model

910

Modification notes

18.07.2019

Work procedure revised

The whole document

Shown on engine 651 with code MJ8 (ECO start/stop function)

1

Brake booster

4

Thrust rod

7

Brake lines

2

Vacuum sensor

5

Vacuum line

8

Electrical connector

3

Nuts

6

Brake fluid reservoir

Shown on engine 780.703

2

Vacuum sensor

9

Vacuum sensor

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.

AS00.00-Z-0035-01A

 Caution

Risk of poisoning from swallowing brake fluid. Risk of injury from skin and eye contact with brake fluid

Only pour brake fluid into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

AS42.50-Z-0001-01A

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Topical note

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

Topical note

Notes on repairs to brake system

AH42.00-P-0003-01A

Topical note

Notes on externally invisible brake fluid loss

AH42.10-P-9406-02A

Topical note

Brake fluid notes

AH42.50-P-0001-01A

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

Topical note

Notes on carrying out repair work in the vehicle interior

AH68.00-N-0001-01S

 

Remove/install

1

Remove vacuum in brake booster (1).

 To do this, operate brake pedal several times.

2

Extract brake fluid from brake fluid reservoir (6).

 To do so, open (6) brake fluid reservoir.

 Commercially available devices/tools
Extraction bellows

3

Remove brake lines (7) from master brake cylinder and release from hydraulic unit.

Note on calculation of tightening torque when using insertion or socket tools with various effective lengths

AH00.00-P-0015-01CW

 Collect escaping brake fluid using suitable rags and seal openings.

 Retaining screw, brake line to hydraulic unit

*BA42.10-N-1003-14TS

 Retaining screw, brake line to master brake cylinder

*BA42.10-N-1004-14TS

 Box wrench bit

*140589000300

 Record plug

*129589009100

4

Disconnect electrical connector (8).

5

Remove master brake cylinder.

If the brake booster (1) is to be replaced.

AR42.10-D-0300TS

 Do not remove brake fluid reservoir (6) from master brake cylinder.

6

Remove vacuum line (5) from brake booster (1).

 Plug openings.

 Installation: Inspect gasket for damage.

 Record plug

*129589009100

If corresponding findings are present,



Replace seal.

7

Disconnect electrical connector of vacuum sensor (2).

Model 910 with engine 651
with code MJ8 (ECO start/stop function)
Model 910 with engine 780.703

8

Disconnect electrical connector of vacuum sensor (9).

Model 910 with engine 780.703

9

Remove push rod (4) from brake pedal.

AR29.10-D-4210TS

 Do not remove pedal bracket.
The ball socket cage on the brake pedal must be replaced.

10

Remove nuts (3).

 Nut, brake booster to firewall

*BA43.10-N-1001-01TS

11

Remove brake booster (1).

 Installation: Inspect gasket for damage.

If corresponding findings are present,



Replace seal.

12

Remove vacuum sensor (2).

Model 910 with engine 651
with code MJ8 (ECO start/stop function)
Model 910 with engine 780.703
If the brake booster (1) is to be replaced.

 To do so, pull vacuum sensor (2) out of brake booster (1).
Seal off opening.

 Installation: Inspect gasket for damage.

 Record plug

*129589009100

If corresponding findings are present,



Replace seal.

13

Remove vacuum sensor (9).

Model 910 with engine 780.703
If the brake booster (1) is to be replaced.

 To do so, pull vacuum sensor (9) out of brake booster (1).
Seal off opening.

 Installation: Inspect gasket for damage.

 Record plug

*129589009100

If corresponding findings are present,



Replace seal.

14

Install in the reverse order.

15

Bleed brake system.

AR42.10-D-0010TS

 Brake lines, brake hoses

Number

Designation

Model 907, 910

BA42.10-N-1003-14TS

Retaining screw, brake line to hydraulic unit

Nm

14

 Brake lines, brake hoses

Number

Designation

Model 907, 910

BA42.10-N-1004-14TS

Retaining screw, brake line to master brake cylinder

Nm

14

 Brake booster

Number

Designation

Model 907, 910

BA43.10-N-1001-01TS

Nut, brake booster to firewall

Nm

23