i did a bit of research on ulsd a while back and the cause of leaking pumps is the ulsd the sulfur is what keeps all the seals swelled and sealing. With the reduction of sulfur from 500ppm to some tiny number like 15ppm all of the natural rubber shrinks and starts to allow leakage and eventualy premature failure of injection pumps, mechanical lift pumps that have rubber diaphrams, and various "rubber soft seals" that have contact with fuel. also part the problem that some may get from b100, svo or wvo a total lack of sulfur plus it's solvent like properties causing fuel leaks. to get around the b100,svo,wvo just changing to a synthetic rubber lines usally solves the problem. as for ulsd, the use power service products, marvelous mystery oil or any fuel lube additive if it will help prevent any problems is unknown due to the fact of who really know that is in any of these products