turn large black plastic locking collar a/clockwise,note where the three locating indents go on top of filter when you pull it down and out.usually pre fill filter with fuel then wont have any problems with air in system.you can feel up in filter mount where the three indents sit,if they are not located you will have problems with the locking collar.apply pressure up with one hand while turning locking collar clockwise,you should feel the collar click into place good luck
wickham
June 2010