500 gal diesel skid tank has been here for 15 years & has a hand pump of the push-in - pull-out type. New Holland needed fuel so I put on a new canister screw-on filter & commenced to pump away. Or tried to; Couldn't hardy force it in or out & no fuel coming out. Had always operated easily. Took the hose off where it came out the filter & easily filled fuel jug. Collapsed hose? Took hose off at the nozzle & 3 inch long strands of old grass completely plugged the 3/4" hose. Cleared the grass & worked as easily as always. The nozzle fits in the nozzle shield & baling wire keeps the nozzle tight in the shield so it can't fall out or rain can't get in. About 1/8" of space between the shield & the nozzle. What could've drug many 3 inch strands of grass thru 1/8" space & down thru the diesel fumes to plug the hose? Only thing I've seen similar was a bug had chewed up grass into short pieces & plugged my weedeater muffler till it wouldn't start. What did it & why did it do it?