Hi Marius.
If you need any help from Combilift go to the web site and you can either link to the technical help (scroll to the bottom and select "Technical Support", or you can chat on the "chat bot", and they will point you in the correct direction.

The correct way to purge the front steering system is as follows.
Park truck in safe location
Start the machine
Apply parking brake
Place the directional lever into sideways position (either left or right)
Let the wheels complete its directional movement
Place the machine on full acceleration.
Turn the steering wheel clockwise until you find the steering wheel come under pressure.
Turn the steering wheel through the pressure for approx. 1 min.
Release the steering wheel and release full acceleration from the machine.
Select forwards/reverse mode.
The 2 front wheels should now align correctly.
Process may need to be repeated.
Best to drive forward and backward after this to check as there may be some tension held in the rubber on the wheels depending on the surface.

Hope this helps.
Richard