Bleeding the clutch hydraulic drive (BMW 3 Series E21)

Clean the bleed nipple on the slave cylinder from dust and dirt and unscrew it by about 1.5 turns. Put a hose on the nipple head and immerse its lower end in a clean container with hydraulic fluid.

Pour fluid into the hydraulic reservoir.

Press the clutch pedal sharply and tighten the bleeder screw. Gradually release the clutch pedal.

Repeat these operations several times, tightening the nipple while the clutch pedal is in the forward extreme position, until bubbles stop coming out of the hose.