This is an old thread but, happen to blow a fuel filter today and couldn't remember how I changed it the last time. This time I made a Word doc, so I'll paste it in here, at the risk of being repetitious. These are my notes-to-self. Hope it helps someone in the future.
JD310A Fuel Filter Replacement
When changing fuel filter, loosen the white plastic knob, below glass sediment bowl first, to drain fuel, If bowl doesn't empty in a couple minutes, loosen round darker knob directly against underside of bowl, which is attached to the hollow attachment bolt. Drain remainder of fuel, remove bowl and element. There is an"o" ring up inside of the filter body, which can be replaced.
The tiny "o" ring may be for the white plastic knob under sediment bowl. Replace upper and lower filter gaskets. Upper filter gasket can be mounted in groove up inside filter body. Lower gasket can be placed in "shelf" of sediment bowl.
Hold assembly by bottom of attachment bolt and screw into Filter body. Tighten by hand first, but then use pliers to make round darker knob and white plastic screw snug, or they will leak.
Make sure air in filter is purged as follows;
Open upper white plastic screw on top of filter body, To the right about 1 foot away is the fuel pump. On the lower right side of the fuel pump is a thin metal lever, push/pull the lever which acts as a hand pump to pump fuel into the filter and pushes the air out threw the top white plastic screw on the filter body. It may take 10-20 pumps of the lever until fuel come out of white screw vent. when it does stop pumping and tighten white plastic screw to close vent. Engine should then start, without having to mess with injector lines, etc.