1/4" hose does the trick. I used Goodyear fuel injection hose from Auto Zone. I'm thinking that if it will handle gasoline, it will handle diesel. Little trick; cut the hose a little bit long and duct tape the new ones to the old ones. Gently pull the new ones with the old ones to get them routed the same way. We are talking low pressure here, not even 10#. Don't need to get high pressure hose. Pretty simple job. Good idea to take the 2 bolts holding the filter off and pulling the filter up to get at the hose clamps. Good time to look at the hose feeding the filter too. 3/8" hose for the feed line.
Ted