Def filter.

How often should you change Def filter, and what happens if you don't change it?

 

I used to change mine twice a year. If u dont change it . it get clogged up like any other filter..on the cummins u will need a 12 point socket to get it. 32mm if i remember

 

Probably throw a code…… the aftermarket one I had on my 1994 379 I did every year regardless of mileage. The 2010 I’m up I’m still new at it but I’ve had my 2014 3 years and I’m at about 90k and still running like a champ. Rumor is they could go about 300k before you bake them. Depends on your application on what you do. I always kick up the idle if I’m not moving.

 

Talking DEF filter or the DPF?

Two very different items with different service intervals.

 

Def filter i did mine every 3 months or every 40,000 miles which ever came first. If you mean the DPF itself i.e something like this

5579366 by PETERBILT - Diesel Particulate Filter (DPF)

I personally would clean it every 75,000-100,000 miles and have the EGR cleaned at the same time. Plus full on replace it every 500,000 miles. Though usage will effect that a lot. My numbers are assumeing a heavy use on/off road truck like my own that is forced to idle a lot becsuse PTO. A dry van may be able to get away with much looser tolerances. Also just replace the DEF quality sensor every year. It goes bad so often that it will save you a lot of time. And for the nox sensors my manual says every 50-75K miles to replace them. So id do them every 6 months just to head off the little red light of doom. Because NO one likes seeing this.



Oh and id replace the doser yearly as well. It tends to get clogged a lot.

Now before someone says it, do you NEED to do it that way? Likely no. Should you just to do everything in your power to avoid the little red light of wallet sadness? YES.

 

Normally change my DEF filter yearly and forgot this year. 2 weeks ago notice a leak under the truck and ya the filter cap along with just about everything under the truck was covered in the white crystal stuff... Was wondering why i was blowing through so much DEF, ( DUH should have clicked in my head ) It threw a derate code as well but I have the OTR reset tool and was able to clear it.

But ya, for this filter it was like $108 from Peterbilt, Highway robbery!!!

 

Get permanent cleaning done and forget about that bs

 

Care to elaborate…….. a filter is a filter….. I’m still learning the system. I’ve never been told from what your saying and understanding of a permanent filter that’s needs not to be exchanged……

 

I think he's talking about deleting the system.