Bleeding the Clutch Hydraulic System

GENERAL INFORMATION

Bleed the clutch hydraulic system if the clutch does not disengage properly when shifting gears, if the clutch pedal returns slowly or does not return, or if the hydraulic system has been opened.

Since the clutch hydraulic system uses brake fluid, read the Bleeding the Brake System subsection.

CAUTION

Brake fluid is poisonous. Never draw fluid by mouth through the hose. Store the fluid only in containers that are inaccessible to children.

PROCEDURE

1. Raise and support the vehicle on stands. Remove the engine compartment undercover. Refer to the Engine Compartment Undercover Removal and Installation subsection.

2. Check the brake fluid level in the master cylinder reservoir. If necessary, top up to the Max mark.

3. Remove the dust caps from the bleeder screws on the slave cylinder and on the front left caliper.

4. Carefully loosen and tighten the bleeder screw.

5. Attach a transparent hose to the bleeder screw on the caliper.

6. Fill the hose with brake fluid. To do this, open the bleeder screw on the caliper. Ask an assistant to slowly depress the clutch pedal and hold it down. Close the bleeder screw and release the pedal. Then open the bleeder screw again and depress the clutch pedal again. Repeat until the hose is filled with fluid. Pinch the hose with a finger to prevent fluid from spilling.

CAUTION

Do not let the fluid level in the reservoir drop significantly. Otherwise, top up the fluid....

7. Connect the free end of the hose to the slave cylinder bleeder screw and open both bleeder screws.

8. Press the brake pedal, close the bleed screw on the caliper and release the brake pedal. Repeat this procedure as many times as necessary until there are no air bubbles in the reservoir. Keep topping up with new fluid during this process.

9. Close the bleed screws on the caliper and the wheel cylinder. Remove the hose and install the dust caps.

10. Lower the vehicle to the wheels.

11. Fill the reservoir with brake fluid up to the Max mark.

12. Press the clutch pedal several times. This will check whether any remaining air in the system is released into the reservoir.

13. Check the operation of the brake system and the clutch actuation system.

CAUTION

If air remains in the system after this procedure, it can be identified by an abnormal noise when shifting gears and poor clutch release. In this case, the air must be removed at a service workshop using special equipment.

14. Install the engine compartment undercover. Refer to the subsection Removal and Installation of Engine Compartment Undercover. Bleeding Air Using a Special Device

In service workshop conditions, air is bled from the hydraulic system using a special device. This device applies a pressure of 2.5 bar to the brake fluid in the reservoir.

15. Unscrew the brake fluid reservoir cap. Fill the fluid up to the Max mark. Connect the device according to the instructions without switching it on.

16. Connect the hose to the bleed screw (arrow in the accompanying illustration) of the wheel cylinder (B), for example, V.A.G 1238 B/3. Lower the end of the hose into a container filled with brake fluid or connect it to the container of the bleeding device.

17. Open the bleed screw and keep it open until no more air bubbles emerge.

18. Press the clutch pedal several times.

19. Fill the reservoir with fluid up to the Max mark. Screw the cap onto the reservoir.