Connect to adapter (Ms. 554-01) device for checking the cooling system and the valve in the plug of the expansion tank. Start the accessory pump to pressurize the cooling system.
Switch off the pump at a pressure of 0.1 bar below the calibration value of the valve pressure in the plug of the expansion tank.
Note. The pressure must not drop. If this occurs, locate the leak.
Gradually unscrew the fitting of the tool to relieve pressure in the cooling system, then remove the adapter (Ms. 554-01) and install the expansion tank cap.