Before pumping, check the fluid level in the tank and add fluid if necessary. Put on the head of the fitting 9 (see fig. 62) the working cylinder is a hose, the lower end of which is immersed in a vessel with a fluid used for hydraulic drive. They sharply press the clutch pedal 3-5 times at intervals of 2-3 s and, holding the pedal depressed, unscrew fitting 9 by 1/2-3/4 turn, displacing the liquid in the drive together with air through the hose into the vessel. After the pedal reaches the extreme forward position and the outflow of fluid through the hose stops, screw the fitting to failure.
Repeat the indicated operation until the air bubbles are completely released and, keeping the pedal depressed, wrap the fitting to failure, remove the hose and put on the fitting cap.
When pumping, make sure that the liquid level in the tank is higher than the hole for the tube going to the main cylinder, and the end of the pumping hose is constantly immersed in the liquid.
If, despite prolonged pumping, air bubbles come out of the hose, then check the reliability of the connections, find out if there are cracks or leaks on the tubes in the connections with the fittings. It is possible for air to enter through faulty O-rings in the master or slave cylinders.