HD uses steel tubes to it's oil filter housing. These tubes slide up into the housing. Special design orings are used. Bought new orings, installed, one leaked again.
Took my trusty fits anything tool out of the toolbox, cotton rope, unwound a strand long enough to wrap around the tube; soaked it with E6000 or Amazing Goop Glue; shoved the tube's nut up the housing; squishing and closing off the oil path down the tube.
Been a year or so since. Haven't heard of the nephew calling out a leak at the tubes.
Ronnie's Harley-Davidson® offers service and parts, and proudly serves the areas of New Ashford, Windsor, Lenox and New Lebanon.
partsfinder.onlinemicrofiche.com
Go to 'oil filter w/ mount' See 11,12, 7 and 8.