HE WAS RAISING SIDE COMPARTMENT OF HOOD ON POWDER TRUCK IN ORDER TO CHANGE FAN BELTS. HOOD WAS HEAVE DUE TO MUD BUILDUP UNDERNEATH. HE WASN'T AWARE OF EXTRA WEIGHT OF HOOD; WHEN ATTEMPTING T O LIFT, HE ENCOUNTERED MORE WEIGHT THAN HE WAS ABLE TO LIFT AND DROPPED HOOD BACK TO ITS RESTING PLACE.