Have an 816 with 250 cummins motor was rebuilt 1980. New pump was put on 8 years ago. The drip is located on the front of pump . there is one bolt at 8 o clock and another at 4 o clock and 1 allan bolt at 6 o clock . It only drips sometimes and not much maybe 4 ounces then it wont drip for awhile. Does not drip when engine is running checked for cracks in the housing both sides are dry... Does anyone know the purpose of the allan screw at the bottom??? Looked in TM no luck. Any insight would be appreciated Thanks Scott The drip is diesel.