Audi Workshop Service and Repair Manuals

Note:

The complete brake master cylinder and brake servo can be replaced separately from each other.

• Longitudinal member with assembly mounting
• Bracket
• Hexagon bolt, 25 Nm
• Rubber mount
• Fitted bolt, 8 Nm
• Self-locking nut, 25 Nm

• Brake servo
• ◆ The required vacuum is taken from the intake manifold.
• ◆ Functional test
• ‒ With the engine switched off, firmly depress the brake pedal several times (this reduces the vacuum present in the servo unit).
• ‒ Now depress brake pedal with moderate force, hold and start engine. If the servo unit is working properly, the pedal will be felt to give slightly when pressed (servo assistance becomes effective).
• ◆ If faulty renew complete.
• ◆ Detach from brake pedal
  .
• ◆ Removing and installing

• Sealing ring
• ◆ Replace
• Brake master cylinder
• ◆ Cannot be repaired. If faulty, renew complete.
• Brake line
• ◆ Brake master cylinder/floating piston circuit to hydraulic unit
• ◆ Tightening torque: 12 Nm
• Brake line
• ◆ Brake master cylinder/push rod piston circuit to hydraulic unit
• ◆ Tightening torque: 12 Nm

• Brake line connection
• ◆ Hydraulic unit to front left brake caliper
• ◆ Tightening torque: 12 Nm
• Brake line connection
• ◆ Hydraulic unit to wheel cylinder/rear right brake caliper
• ◆ Tightening torque: 12 Nm
• Brake line connection
• ◆ Hydraulic unit to wheel cylinder/rear left brake caliper
• ◆ Tightening torque: 12 Nm

• Brake line connection
• ◆ Hydraulic unit to front right brake caliper
• ◆ Tightening torque: 12 Nm
• ABS hydraulic unit with control unit
• ◆ Do not unplug connector for control unit before self-diagnosis.
• ◆ Removing and installing
• Hexagon bolt, 25 Nm