Verify that the green and white accordions are in the right position in the injection head. You can take them out completely to see if this is the cause of the difficulty.
Verify the injection head's rods (which are covered with the green and white accordions) are going into the appropriate place in the hand unit. The green accordion in the paper hole and the white accordion in the lower hole.
Close the green nut properly.
Written by Assaf ShafranUpdated over a week ago