Clutch hydraulic system — bleeding (Audi 100 C3)

1. If part of the hydraulic system has been dismantled, or if air has accidentally entered the system, it must be bled. Pedal dips indicate the presence of air in the system (which decrease if the pedal is pumped several times).

2. The design of the clutch hydraulic system does not allow bleeding using the normal clutch pedal method. Bleeding equipment must be used to remove all air from the system.

3. The bleed equipment must be connected to the hydraulic system according to the manufacturer's instructions. The system is normally bled through the clutch slave cylinder bleeder port, which is located on top of the transmission case.

4. The system is pumped until the liquid being driven is free from air bubbles. The bleed valve is then closed and the bleed equipment is disconnected.

5. Check clutch action. If there is still air in the system, repeat bleeding.

6. Do not reuse leaked fluid from the system, even if it appears clean. Hydraulic fluid absorbs water and repeated use can cause internal corrosion of the master and slave cylinders, causing excessive wear and seal failure.