Hydraulic Unit and Brake Booster/Master Cylinder Assembly Overview, Mark 25 E1, from 27 November 2006
Hydraulic Unit and Brake Booster/Master Cylinder Assembly Overview, Mark 25 E1, from 27 November 2006
1 Anti-lock Brake System (ABS) Control Module (w/Electronic Differential Lock (EDL)) (J104)
• Removing and installing, refer to => [ Anti-lock Brake System Hydraulic Control Unit, Mark 25 E1, from 27 November 2006 ] Service and Repair.
2 ABS Hydraulic Unit (N55)
• Removing and installing, refer to => [ Anti-lock Brake System Hydraulic Control Unit, Mark 25 E1, from 27 November 2006 ] Service and Repair.
3 Brake Line
• Master cylinder/primary piston circuit to hydraulic control unit.
• Identification at hydraulic unit - DK -.
4 Brake Line
• Via the intermediate piece to the right front brake caliper.
• Identification at hydraulic unit - VR -.
5 Brake Line
• To the left front brake caliper.
• Identification at hydraulic unit - VL -.
6 Brake Line
• Master cylinder/secondary piston circuit to hydraulic unit.
• Identification at hydraulic unit - SK -.
7 Brake Line
• Via the intermediate piece to the left rear brake caliper.
• Identification at hydraulic unit - HL -.
8 Brake Line
• Via the intermediate piece to the right rear brake caliper.
• Identification at hydraulic unit - HR -.
9 Intermediate Piece
10 Bracket
• Allocation, refer to the parts catalog.
11 Bolt
• 8 Nm
12 Hex Flange Bolt
• 9 Nm
13 Rubber Insulation
14 Bracket
• Allocation, refer to the parts catalog.
15 Gasket
• For the brake booster.
16 Brake Booster
• Included the brake pressure release solenoid (F84) and brake pressure magnetic coil (N247) (not interchangeable).
• On gas engines, vacuum is supplied from the intake manifold.
• Vehicles with a gas engine and automatic transmission are equipped with a brake system vacuum pump.
• On diesel engines, a vacuum pump is installed for vacuum creation.
• Function test:
- With the engine turned off, press the brake pedal firmly several times (to exhaust the vacuum in the unit).
- 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 malfunction (previously, check all vacuum lines).
• Removing and installing, refer to => [ Brake Booster ] Brake Booster.
17 Sealing Plug
• Connection for the vacuum hose.
18 Vacuum Hose
• Insert into the brake booster.
19 Seal
20 Self Locking Nut
• 25 Nm
• Always replace after removal.
21 Bracket
22 Master Cylinder
• Cannot be serviced. Replace as a complete unit if malfunctioning.
• Removing and installing, refer to => [ Brake Master Cylinder ] Service and Repair.
23 Self Locking Nut
• 25 Nm
• Always replace after removal.
24 Sealing Plugs
• Lubricate with brake fluid and press into the brake fluid reservoir.
25 Brake Fluid Reservoir
26 Cap
27 TORX Bolt, 2 + 0.8 Nm
• Tighten diagonally, in steps, without tilting it.
Brake Lines from Master Cylinder, Connecting to Hydraulic Unit
On the Master Cylinder:
On the Hydraulic Unit:
A Hydraulic unit to primary piston circuit of master cylinder
Identification at hydraulic unit - DK -
B Hydraulic unit to secondary piston circuit of master cylinder
Identification at hydraulic unit - SK -
1 Hydraulic unit to left front brake caliper
Identification at hydraulic unit - VL -
2 Hydraulic unit via the intermediate piece to the right front brake caliper
Identification at hydraulic unit - VR -
3 Hydraulic unit via the intermediate piece to the right rear brake caliper
Identification at hydraulic unit - HR -
4 Hydraulic unit via the intermediate piece to the left rear brake caliper
Identification at hydraulic unit - HL -