skromfols

I plan on changing my own Diesel Exhaust Fluid (DEF), rather than paying MB the price that they want. But I need to find a good pump to use to remove old DEF from the tank before it crystallizes. I've been on the internet looking for a good pump, but the only ones I can find that are specific for DEF are for large capacity tanks, which I assume are trucks.

Has anyone found a good pump to use on your Blutec ?

N_Jay

Changing? Don't you just add more. Are you driving so little that it is aging?

skromfols

N_Jay, in an earlier post discussing DEF I was told that the stuff crystallizes with age, so when you take it in for your service MB pumps out what is left and puts in all new. We put about 12,000 - 13,000 miles per year on our vehicles, which is probably about average.

N_Jay

I don't think that would be the case since every fill-up would be a full tank, and MB sells it is (overpriced) little bottles.

skromfols

I'll just have to keep researching it. I sure as hell don't want to buy anything I don't need, but also don't want to cause any unnecessary problems with the fuel system.

N_Jay

There is a GM video that says if you get a warning that DEF quality is low, adding fresh DEF to top up is usually all that is needed.

Considering the number of DEF vehicles out there if it was problem, we would hear a lot more about it (and someone would be selling an overpriced drain and flush system.)

Mbenz260e

From my review of the manuals from 2009-2012 they discussed flushing ever 2yr/20k.

2013 it just discusses adding every 10k.

Likes others have said it depends how fast your burning it.

AtTheMurph

If you are worried about crystallization simply add DEF more frequently. The particulate matter will dissolve back into solution. The reason it might form crystals is because as the tank empties their is more airspace and evaporation and the remaining fluid becomes more concentrated.