What is the reason for being unable to bleed air after replacing the clutch master cylinder?

[LylaFitz]

The reasons for being unable to bleed air after replacing the clutch master cylinder are as follows: Air entering the clutch hydraulic line: If air cannot be bled from the clutch system after replacing the master cylinder, it indicates that air is entering through either the master cylinder pipelines or the connections of the clutch hydraulic line. Air in the clutch master cylinder will cause symptoms such as a soft clutch pedal and incomplete clutch disengagement. It is recommended that the owner visit a 4S shop or repair facility as soon as possible to have professionals bleed the air or replace the connection seals. Method for bleeding air from the clutch master cylinder: To remove air from the clutch master cylinder, first fill the master cylinder with clutch fluid. Then, connect one end of a tube to the bleed screw and the other end to a transparent container. Slowly depress the clutch pedal and gradually loosen the bleed screw. The clutch fluid will flow into the transparent container, and the air will be expelled. This operation cannot completely remove all air in one attempt; the above steps need to be repeated multiple times to fully eliminate the air.