Through 07.04.08

Master Cylinder and Brake Booster Assembly Overview





1 Anti-lock Brake System (ABS) control module (w/Electronic Differential Lock (EDL)) (J104)

Separation of the control module from the hydraulic unit is not possible on vehicles with a hydraulic brake booster or hill assist.

• Removing and installing, refer to --> [ Control Module and Hydraulic Unit ] Service and Repair

2 ABS hydraulic unit (N55)

Separation of the control module from the hydraulic unit is not possible on vehicles with a hydraulic brake booster or hill assist.

• Removing and installing, refer to --> [ Control Module and Hydraulic Unit ] Service and Repair.

3 Brake line

• Tightening specification: 14 Nm.

• Master cylinder/primary piston circuit to hydraulic control unit.

• Identification: 6.5 mm diameter and a fitting with longer M12 x 1 threads.

4 Brake line

• Tightening specification: 14 Nm.

• Master cylinder/secondary piston circuit to hydraulic control unit.

• Identification: 6.5 mm diameter and a fitting with longer M12 x 1 threads.

5 Brake line

• Tightening specification: 14 Nm.

• To the left front brake caliper.

• Identification: 5.25 mm diameter and a fitting with shorter M12 x 1 threads.

6 Brake line

• Tightening specification: 14 Nm.

• To the right front brake caliper.

• Identification: 5.25 mm diameter and a fitting with M10 x 1 threads.

7 Brake line

• Tightening specification: 14 Nm.

• To the left rear brake caliper.

• Identification: 5.25 mm diameter and a fitting with shorter M12 x 1 threads.

8 Brake line

• Tightening specification: 14 Nm.

• To the right rear brake caliper.

• Identification: 5.25 mm diameter and a fitting with M10 x 1 threads.

9 Torx bolt, 5.5 Nm

• Use new bolts.

10 Bracket

11 Bolt, 8 Nm

12 Gasket

• For the brake booster.

13 Brake booster

• On gas engines, vacuum is supplied from the intake manifold.

• Some vehicles with gas engines and automatic transmissions are equipped with a vacuum pump for the brakes. Refer to --> [ Brake System Vacuum Pump ] Brake System Vacuum Pump.

• On vehicles with a hydraulic brake booster, a vacuum sensor is installed. Refer to --> [ Brake Booster Vacuum Sensor ] Brake Booster Vacuum Sensor.

• On diesel engines, a vacuum pump is installed for vacuum creation. Refer to --> [ Brake Booster Vacuum Pump Overview ] .

• Functional test:

- With the engine turned off, press the brake pedal firmly several times (to deplete vacuum in the booster).

- Press and hold the brake pedal with average foot pressure and start the engine. If the brake booster is working properly, the pedal will be felt to give noticeably under foot (booster assistance becomes effective).

• Replace as a unit in the event of a malfunction (previously, check all vacuum lines).

• Removing and installing, refer to --> [ Brake Booster ] Brake Booster.

14 Seal

15 Brake booster vacuum sensor (G483)

• Only on vehicles with a hydraulic brake booster.

• Removing and installing, refer to --> [ Brake Booster Vacuum Sensor ] Brake Booster Vacuum Sensor.

16 Master cylinder

• Allocation.

• Cannot be serviced. Replace as complete unit if malfunctioning.

• Removing and installing, refer to --> [ Master Cylinder ] Master Cylinder.

17 Heat shield

18 Nut, 25 Nm

• Always replace after removal.

19 Sealing plugs

• Lubricate with brake fluid and press into the brake fluid reservoir.

20 Brake fluid reservoir

21 Cap

22 Sealing plugs

• Connection for vacuum hose.

23 Vacuum hose

• Insert into the brake booster.