Audi Workshop Service and Repair Manuals

Note:

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

The bolted connections between the brake master cylinder and ABS control unit are tightened to 25 Nm.

• Sealing ring
• ◆ Replace
• Brake master cylinder
• ◆ Cannot be repaired. If faulty, renew complete.
• ◆ Removing and installing

• Self-locking nut, 25 Nm
• Sender -G201 for brake pressure -1-
• ◆ Removing and installing
• Brake line
• ◆ Brake master cylinder/push rod piston circuit to hydraulic unit
• ◆ Tightening torque: 25 Nm
• Brake line
• ◆ Brake master cylinder/floating piston circuit to hydraulic unit
• ◆ Tightening torque: 25 Nm
• Brake line
• ◆ Brake master cylinder/push rod piston circuit to hydraulic unit
• ◆ Tightening torque: 25 Nm

• Brake line
• ◆ Brake master cylinder/floating piston circuit to hydraulic unit
• ◆ Tightening torque: 25 Nm
• Brake line connection
• ◆ Hydraulic unit to front 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

• 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
• Longitudinal member with assembly mounting
• Fitted bolt, 8 Nm
• Hexagon bolt, 25 Nm
• Hexagon bolt, 25 Nm
• Bracket for 1.4 petrol engines
• Bracket for 1.4 TDI engines
• Rubber mount

• 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