Remove/install master brake cylinder

AR42.10-P-0300MFA

Remove/install master brake cylinder

16.01.2020

Model

118, 177, 247

Modification notes

15.01.2020

Document completely revised.

Shown on model 177.0 with engine 282 except code ME08 (Hybrid drive 75-84 KW VARIANT (INCLUDING PLUGIN))

1

Brake fluid reservoir

6

Master brake cylinder

2

Brake lines

7

Electrical connector

5

Nuts

Shown on model 177.0 with engine 282 with code ME08 (Hybrid drive 75-84 KW VARIANT (INCLUDING PLUGIN))

1

Brake fluid reservoir

4

Electric line

6

Master brake cylinder

2

Brake lines

5

Nuts

7

Electrical connector

 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.Model 177, 247 with engine 282
with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AS00.00-Z-0035-01A

 Danger

Risk of accident when commissioning the vehicle due to a lack of braking effect when the service brake is operated for the first time after repair work.

Before starting the engine, actuate brake pedal several times until pressure is built up and maintained in the brake system.

AS42.50-Z-0002-01A

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

 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

General information on vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system as well as personal protective equipment

Model 177, 247 with engine 282
with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AH00.00-Z-0300-01A

Topical note

Notes on repairs to brake system

AH42.00-P-0003-01A

Topical note

Brake fluid notes

AH42.50-P-0001-01A

Notes on safety-relevant components

AH00.00-Z-0019-01A



Remove

1

Reduce vacuum in brake booster by depressing brake pedal several times.

2

Remove battery carrier.

AR54.10-P-0028MFA

3.1

Remove holders for power electronics.

Model 177, 247 with engine 282
with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AR08.00-P-0005MFH

3.2

Remove heat shield for firewall until the master brake cylinder (6) is accessible.

Model 118 with engine 282
Model 118, 177, 247 with engine 139
Model 118, 177, 247 with engine 260
Model 118, 177, 247 with engine 608
Model 118, 177, 247 with engine 654
Model 177, 247 with engine 282
except code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

Model 118, 177, 247 with engine 260

AR49.10-P-0001MFC

Model 118 with engine 282
Model 177, 247 with engine 282
except code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AR49.10-P-0001MFD

Model 118, 177, 247 with engine 608

AR49.10-P-0001MFE

Model 118, 177, 247 with engine 654

AR49.10-P-0001MFF

Model 118, 177, 247 with engine 139

AR49.10-P-0001MFG

4

Extract brake fluid from brake fluid reservoir (1).

5

Release and disconnect electrical connector(7).

6

Unclip electric line (4) from master brake cylinder (6).

 Clip remover

*452589016300

7

Mark brake lines (2) relative to master brake cylinder (6).

8

Remove brake lines (2) from master brake cylinder (6).


Collect brake fluid which runs out with an absorbent rag.
The paint will be damaged otherwise.

 Box wrench bit

*140589000300

 Adapter coupling

*001589001600

9

Seal exposed connections using suitable plugs.

 Record plug

*129589009100

10

Unclip brake lines (2) from bracket and press lightly to one side.


Do not kink or crush brake lines (2).
Otherwise damage will occur.

11

Remove nuts (5).

12

Remove master brake cylinder (6) with brake fluid reservoir (1).

13

Detach brake fluid reservoir (1) from master brake cylinder (6).

When replacing the master brake cylinder (6).

AR42.10-P-0308MFA



Install

14

Attach brake fluid reservoir (1) to master brake cylinder (6).

When replacing the master brake cylinder (6).

AR42.10-P-0308MFA

15

Position master brake cylinder (6) with brake fluid reservoir (1) on brake booster.

16

Install nuts (5).

 Nut, master brake cylinder to brake unit

*BA42.10-P-1001-05G

17

Remove stop plugs from connections.

 Record plug

*129589009100

18

Clip brake lines (2) into holder and position on master brake cylinder (6).

 Observe markings.

19

Attach brake lines (2) to master brake cylinder (6).

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

AH00.00-P-0015-01CW

 Retaining screw, brake line to master brake cylinder

*BA42.10-P-1002-04Q

 Box wrench bit

*140589000300

 Adapter coupling

*001589001600

20

Clip electric line (4) onto master brake cylinder (6).

21

Connect and lock electrical connector (7).

22.1

Attach heat shield for firewall.

Model 118 with engine 282
Model 118, 177, 247 with engine 139
Model 118, 177, 247 with engine 260
Model 118, 177, 247 with engine 608
Model 118, 177, 247 with engine 654
Model 177, 247 with engine 282
except code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

Model 118, 177, 247 with engine 260

AR49.10-P-0001MFC

Model 118 with engine 282
Model 177, 247 with engine 282
except code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AR49.10-P-0001MFD

Model 118, 177, 247 with engine 608

AR49.10-P-0001MFE

Model 118, 177, 247 with engine 654

AR49.10-P-0001MFF

Model 118, 177, 247 with engine 139

AR49.10-P-0001MFG

22.2

Install holders of power electronics.

Model 177, 247 with engine 282
with code ME08 (Hybrid drive 75-84 kW VARIANT (INCLUDING PLUGIN))

AR08.00-P-0005MFH

23

Install battery carrier.

AR54.10-P-0028MFA

24

Bleed brake system.

AR42.10-P-0010MFA



Check

25

Perform brake test on test stand.



AP42.00-P-4290BA

 Master brake cylinder

Number

Designation

Model 118

Model 177

BA42.10-P-1001-05G

Nut, master brake cylinder to brake unit

Nm

23

23

 Master brake cylinder

Number

Designation

Model 247

BA42.10-P-1001-05G

Nut, master brake cylinder to brake unit

Nm

23

 Brake lines

Number

Designation

Model 118

Model 177

BA42.10-P-1002-04Q

Retaining screw, brake line to master brake cylinder

Nm

16

16

 Brake lines

Number

Designation

Model 247

BA42.10-P-1002-04Q

Retaining screw, brake line to master brake cylinder

Nm

16