DEF

DEF LEPPARD

 

I've said this before and I'm sorry if its a broken record, but New Def, Good Def, Old Def... There is NEVER a good time for Def!! I'd rather be talked to like trash, spit on by 3 ###### at one time, run over by everybody in this forum than to EVER buy another truck with Def. Sorry guys im very bitter..

 

I agree theres never a good time for def. As a mechanic I see bad things almost every day. However, a lot of the issues I've been seeing can be avoided by a small amount of driver maintenance. Granted, most of my work is done on PACCAR and a decent bit of Cummins.

I also fault some of my fellow mechanics for not trying to educate the willing...

 

Educate me, what proper driver maintenance can I do?

 

Aside from making sure you dont put diesel in the def tank or anything like that, it is mentioned in service manuals that it helps to never let the tank get below 25%. It helps to NOT idle the truck for extended periods of time. Do NOT add anything other than DEF into the DEF tank (I have seen people add various de-icing agents lately). When you get PM's done on your truck, ask for the differential pressure sensor to be cleaned (takes the mechanic 5 minutes if that). Do not pee, add water, or believe everything you hear in regards to DEF. Cummins offers drivers various educational brochures specifically on their aftertreatment systems. Explore and read OEM manuals and you will be able to avoid most issues. And dont, drive through the lights.

 

Usually gets filled every third or fourth trip around 1/8 usually due to only one place on my run having it at the pump. Didn't know that it had a differential pressure sensor, I'll ask my mechanic next time to clean it. Where is it?

 

How often does the filter need changed, really? And what about the def doser? Does the def system ever need to be flushed? Thinking about crystallization in the system.

 

Depending on the system, the differential pressure sensor is typically on top of the DPF filter canister (the large metal canister underneath passenger step on most semi's) some can be cleaned others just replaced.

 

Ok, my canister is behind the steps completely on an international. Actually looks like 2 mufflers side by side and I'd hate trying to take anything off the top but will look closer next time I grease it