Clutch Hydraulic System Bleeding
Bleed the clutch hydraulic system after disconnecting the hydraulic tubes or hoses, after removing the clutch master cylinder, or when air is suspected in the clutch hydraulic system (spongy clutch pedal).
Use only the recommended brake fluid.
Do not mix it with other types or brands of fluid.
Recommended fluid: SAE J1703 (DOT 3) brake fluid
1. Loosen the bleeder screw on the clutch release cylinder body.
2. Slowly pump the clutch pedal until no more air bubbles come out.
3. Hold the clutch pedal depressed and tighten the bleeder screw.
4. Fill the clutch fluid reservoir with the recommended fluid.

Rapid pumping of the clutch pedal within the range "B" to "C" may push the release cylinder piston out of the release cylinder body during bleeding. Depress the clutch pedal again only after it has fully returned to position "A".
Test yourself
A quick Hyundai Elantra CN7 quiz: every answer comes with an explanation and a link to the manual page.