[CaptainGizmo]

I realize that the majority of the Gurus are "pre-Def'rs", but for those of us who are less fortunate, this will be of value.  Maybe...you can tell a friend in need. 

I've posted this on the VIP group on FB, just to get the word out.

After quite a bit of research, I've learned that the DEF Doser is recommended to be replaced EVERY YEAR!  The injector gets corroded, and the efficiency diminishes and won't REGEN as effectively.  This can cause excess DEF leaking, Faults, and even a Derate.

In the case of my 2015 ISX, I have a strong feeling that's why I've got DEF crystals forming under my filter.  Plus, I'm seeing white specks stuck to the back of my rig and TOAD.

   

Kinda interesting how CUMMINS didn't mention, or have a clue about this after I've asked several times!

I first saw this info from a large diesel mechanic on youtube, but did more digging and found a CUMMINS schedule chart...and guess what?  Yup...every 12 months!  Yes, it says 150k, but REMEMBER...just as with tires, our coaches will AGE-OUT before MILING-out!  So, it's the case of "whichever comes first".

   

Anyway, Cummins sells them for around $200, but the diesel shops suggest that you can get an eBay (or Amazon) version for $30 which works just fine.  So, I'll give that a shot!  I mean, what could go wrong? 

BTW, I think we're in luck in terms of accessing the doser.  It appears as though Newell has a Stainless access panel between the battery and engine, which means we can access it from the TOP...wouldn't that be a welcomed change!