Hayter 13/30Ride-on Lawnmower?

The Mower housing on my Hayter 13/30 ride-on lawnmower has dropped. Although the rear of the housing lifts when I go from 1 to 6 on the cut height lever, the front remain on the deck. Going through the manual drawings, I cannot see anything missing or any bolts missong. Any help would be appreciated. Thanks, Bob