Master Cylinder and Brake Booster Assembly Overview
Master Cylinder and Brake Booster Assembly Overview
1 ABS Control Module (w/EDL) (J104)
Separation from control module and hydraulic unit is not possible on vehicles with hydraulic brake booster or hill assist.
• Removal and installation, refer to => [ Control Module and Hydraulic Unit ] Control Module and Hydraulic Unit.
2 ABS Hydraulic Unit (N55)
Separation from control module and hydraulic unit is not possible on vehicles with hydraulic brake booster or hill assist.
• Removal and installation, refer to => [ Control Module and Hydraulic Unit ] Control Module and Hydraulic Unit.
3 Brake Line, 14 Nm
• Master brake cylinder/primary piston circuit to hydraulic control unit.
• Identification: diameter 6.5 mm and tube fitting with longer thread M12 x 1.
4 Brake Line, 14 Nm
• Master brake cylinder/secondary piston circuit to hydraulic unit.
• Identification: diameter 6.5 mm and tube fitting with longer thread M12 x 1.
5 Brake Line, 14 Nm
• To left front brake caliper.
• Identification: diameter 5.25 mm and tube fitting with shorter thread M12 x 1.
6 Brake Line, 14 Nm
• to right front brake caliper.
• Identification: diameter 5.25 mm and tube fitting with thread M 10 x 1.
7 Brake Line, 14 Nm
• to left rear brake caliper.
• Identification: diameter 5.25 mm and tube fitting with shorter thread M12 x 1.
8 Brake Line, 14 Nm
• To right rear brake caliper.
• Identification: diameter 5.25 mm and tube fitting with thread M 10 x 1.
9 Bolt, 5.5 Nm
• Use new bolts.
10 Bracket
11 Bolt, 8 Nm
12 Gasket
• For brake booster.
13 Brake Booster
• On gasoline engines, vacuum is supplied from intake manifold.
• Some vehicles with a gasoline engine and automatic transmission are equipped with a vacuum pump for 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 => [ Vacuum Pump for Brake Booster Assembly Overview, Diesel Vehicles ] Vacuum Pump for Brake Booster Assembly Overview, Diesel Vehicles.
• Function test:
- With engine switched off, depress brake pedal firmly several times (to deplete vacuum in tool).
- Depress and hold brake pedal with average foot pressure and start engine. If brake booster is working properly, pedal will be felt to give noticeably under foot (booster assistance becomes effective).
• Replace as a unit in the event of malfunction (previously, check all vacuum lines).
• Removal and installation, refer to => [ Brake Booster ] Brake Booster.
14 Seal
15 Brake Booster Vacuum Sensor (G483)
• Only on vehicles with the hydraulic brake booster.
• Removal and installation, refer to => [ Brake Booster Vacuum Sensor ] Brake Booster Vacuum Sensor.
16 Brake Master Cylinder
• Cannot be serviced. Replace as complete unit if malfunctioning.
• Removal and installation, refer to => [ Master Cylinder ] Master Cylinder.
17 Heat Shield
18 Nut, 25 Nm
• Always replace after removal.
19 Sealing Plugs
• Moisten with brake fluid and press into brake fluid reservoir.
20 Brake Fluid Reservoir
21 Cap
22 Sealing Plugs
• Connection for vacuum hose.
23 Vacuum Hose
• Insert into brake booster.