Bleeding the clutch hydraulic drive (VW Passat B4)

It is best to remove air from the clutch hydraulic drive using a special installation for bleeding under pressure. The pressure during bleeding should not exceed 2.5 kgf/cm². Bleed the hydraulic drive using the installation first through the nipple of the hydraulic drive master cylinder, then through the slave cylinder.

Remove the bleeding unit and restore the fluid level in the hydraulic drive reservoir to normal.

If there is no special bleeding unit, bleed the clutch hydraulic drive as follows:

• remove the protective cap from the bleed nipple on the working cylinder and attach a hose to it, the lower end of which is lowered into the brake fluid poured into a transparent glass container;
• slightly unscrew the bleed nipple, press the clutch pedal all the way down and release it smoothly;
• repeat the operation several times until air bubbles with brake fluid stop coming out of the hose;
• top up the working fluid in the hydraulic drive reservoir to the normal level;
• screw the bleed nipple onto the working cylinder and install the protective cap on it.

During bleeding, monitor the fluid level in the hydraulic drive tank, preventing its bottom from being exposed. The end of the bleeding hose must be constantly immersed in the fluid.

(The original text can be found on the portal VWManual.ru)