Clutch master cylinder and slave cylinder, notes on removing and installing: Notes

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2008 Audi S4, 2008 Audi RS 4, 2007 Audi S4, 2007 Audi RS 4, and 2006 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.

Before replacing the clutch master cylinder or slave cylinder on the assumption that it is defective you must first perform a function check.
If slave cylinder is removed from transmission with hose/line assembly still attached, make sure you do not press clutch pedal. Otherwise, the piston will be pressed out of the slave cylinder and be destroyed.
After installing the slave cylinder, carefully press the clutch pedal. If you feel an unusually strong point of resistance when depressing the clutch pedal, you must not press it down further. The operating rod of the slave cylinder is likely to have been guided past the clutch release lever. The slave cylinder would then be destroyed once pedal force exceeds approx. 300 N.