Who fills the secondary fuel filter on CAT engines when changing filter

I have always filled my fuel filters with ATF for 30 years !!

 

I've always filled my filters before putting them on.

 

Believe it or not, oil out of a NEW container will FAIL the ISO particle count test. So don't go assuming you're safe just because it was an unopened container of oil.

 

I had clogged filters one night, I always carry spares. But I was along I68 in MD, in middle of nowhere. I dumped the fuel from the old filters into the new ones, and used the primer to finish filling them. Never had an issue, though I will never do that again unless I have no choice....

 

Funny thing..... I been filling oil and fuel filters since the day I became an owner op back in 1984. And never had an issue with an engine, bearings, only one injector on my 3406E and I can’t say it was from filling up the filter.

 

Adding atf or other oils to diesel puts lubricants back in the fuel that is taken out when they make it ulsd. Also helps clean injectors

 

Not ATF, that’s old school for a non electronic engine. I did used ATF for my BC 1 Cummins. Did wonders. Diesel today has “ash” in it to replace the lubricants that was removed. If you want to add more lubricant, 2 stroke oil is the way to go.

 

I fill them every time without exception, usually with clean fuel but at least once a year I fill them with ATF; you're far more likely to damage an injector pushing dry air through it than getting debris in the filter by being careless when filling it.

 

Some of us use both. I’ve even heard some guys pour their used oil in their fuel tanks for the same purpose. If I had a way to keep 10 gallons of black oil clean I would do it to