clogged fuel filters

[flonly]

I have a 2008 kenworth t660 with cm871 and spin on filters.Igot inside of fuel tanks cleaned then after noticed something on bottom.Guy who cleaned them said looked like fuel return line was going bad so does that mean the insides are deteriorate cause of hot fuel?Do i just replace fuel filters till they stay clean?When i dum fuel out of water seperator filter it looks like black dirt.thanks

[tree98]

I'm not sure what your asking exactly????

[flonly]

Has anyone else experienced this and what was the solution?Just keep changing filters till you get everything out of tanks ?Other question is how hot should the return fuel be is there a cooler of some sort Im guessing the hot return lines and 15 years made lines deteriorate inside over time?

[flonly]

Oh and I have replaced all six fuel lines and valve underneath truck

[Rawze]

Cm871 engines make ashpaltine into the return fuel system over time. It is a black substance that builds up if you do not have a davco, and/or are not using 10 micron filters.

[flonly]

Is their additive to put into fuel tanks to get rid of it?I know when they cleaned the tanks they said there was black stuff on tank walls that 1800 psi wouldnt even budge when trying to clean.I only have spin on filters but only use fleetguard since truck was new and now has 1.7 million miles on it and 475000 since inframe at mr haggs

[flonly]

What would be the best asphaltine additive to get rid of it?And im guessing a lot of filters?thanks everone

[DVT873]

Fleetguard, owned by Cummins has a conditioner. I have no idea as to how well it works or how any of these products work in the real world. here is a link.
https://www.cumminsfiltration.com/africa...599_08.pdf