Wheel loaders, like other heavy equipment, can use many different buckets sizes and types. All the buckets will connect with a pin through a hinge on the boom or the arm of the loader. The max hinge pin height is the highest point the arm of the loader can reach. The dump height takes into account the bucket on the loader and is the height of the lowest point of the bucket at the point of discharge if the bucket is tipped in a position where it can dump whatever it's carrying. The max dump height can best be pictured as how high a wall could you dump material over. The hinge pin height will be higher than the max dump height since the bucket rotates around the hinge and the bucket at the point of discharge will be lower than that since it will have to be tipped downward to discharge. I hope that helps.
