01 chev duramax last nit i was talking with a gm grand master tech on this web site he asked me to see if the fuel was running down the back of the block. it is . i replaced the return line seal. still leaking fuel from back of engine. both main feed and return lines are not leaking 120000 miles on truck. fuel system was replaced at 50000 by gm. this is going to have to get in the hands of gm tech that worked on the line for at least 10 years.
i also am a tech for the last 38 years i'm looking for a spot to start insted of tearing down the entire top end but i will if i have to.