Screw in the device adapter instead of the radiator cap.
Caution: Cover the radiator connection with a rag for safety reasons. Remove the radiator cap only when the radiator has cooled down to at least human body temperature. Sometimes hot water splashes can cause burns.
Pressurize the cooling system with a pump. The pressure should be 1.8 bar.
The pressure should not drop within 2 minutes. If pressure drops, look for leaks.
Relieve pressure and slowly roll up adapter.
Check safety valve. It is located in the radiator cap. His task is to open the system and drain the coolant into the expansion tank.
To check the safety valve, screw the filler cap onto the instrument as shown in Fig. G-1808.
Create pressure. In the pressure range of 0.7-1.0 bar the valve should open. Otherwise, replace the cover.
Screw the cap onto the radiator neck.
If the rubber seal is damaged, replace it.