Clutch Master Cylinder — Removal and Installation (Audi A6 C5)

Caution! If you suspect a fault in the master or slave clutch cylinders, you must check their functionality before starting to dismantle them.

To provide access to the clutch master cylinder, it is recommended to remove the fairing. The engine control unit can also be moved to the side without disconnecting the plugs from it.

Removal

1. Disconnect the negative (-) battery terminal.

2. Remove the relay block located next to the engine control unit by pressing the retaining leashes (see arrows in the illustration), and remove the wires from the mounting groove together with the sleeve.

3. Unscrew the mounting bolts and remove the engine control unit tray.

4. Clamp the brake fluid hose A on the reservoir with a suitable clamp, such as AUDI-3094, and disconnect it from the brake master cylinder (see illustration). Plug the hose opening with a suitable plug.



5. Use a screwdriver to pry up and remove clamp C, which holds line B on the master cylinder, remove the clamp and disconnect the line (see illustration 3.4).



6. Remove the storage pocket above the driver's side footwell.

7. Remove the retaining clip 1, remove the connecting pin that secures the master cylinder/vacuum booster pushrod to the brake pedal (see arrow 2 in the illustration), and disconnect the pusher.

Caution: Remove the clutch pedal sensor, if present.

8. Unscrew the mounting bolt and remove the support bracket together with the pedals after disconnecting the master cylinder pusher from the clutch pedal.

9. Unscrew the clutch master cylinder mounting bolts and remove it.

Installation

Installation of the clutch master cylinder is performed in the reverse order of its removal.

10. Bleed the clutch hydraulic system after installing the master cylinder.

11. Install the clutch pedal position sensor. It is recommended to install a new pedal sensor. The sensor can only be reused once.

12. Make sure that the clutch pedal position sensor 1 is installed correctly. The sensor should fit tightly against the pedal 3, and the distance "a" between the clamp and the support bracket 2 of the pedal, as well as the offset "b" of the sensor plunger should not be more than 0.5 mm. In order to adjust the specified offsets, the sensor should be turned while holding the clamps (see illustration).