Auto Disk Leaking

One fix is to reduce the amount of clearance between the hopper and the disk by carefully sanding down the risers that the hopper is mounted to.  Place a disk between the risers with a piece of scotch tape on top, and use a file or sandpaper attached to a flat surface, and file/sand until contact is made with the scotch tape.

Another is to purchase the update kit (catalog #90377) which includes a hopper with a soft plastic wiper in the base, which is in light contact with the disk when the hopper is attached.  This strikes off the disk as it slides under to drop the charge.