Found something scary about DEF fluid quality in my fleet logs

I was going through my maintenance records for our delivery trucks last week and I noticed 4 out of 6 trucks had injector issues within 2 months of each other. Turns out the DEF we were buying from a new supplier near Portland had way higher sediment levels than the spec allows, like 50 parts per million over the limit. Ran a simple test with a refractometer and it was obvious - has anyone else checked their bulk DEF supply for purity before it hits the tanks?

2 comments

2 Comments

rivera.henry1mo ago

Hold on a second, you said a refractometer picked up sediment levels? Refractometers measure how light bends through a liquid, they don't really pick up solid particles like sediment. You need a different test for that, maybe a simple filter test or a turbidity meter. The refractometer is good for checking the urea concentration to see if it's watered down, but not for dirt floating in it. I'd double check with a proper sediment test cause that's two different problems.

the_miles1mo ago

Man that's rough, nothing worse than finding out a supplier is cutting corners on something as critical as DEF fluid. @rivera.henry makes a good point about the refractometer though, I'd trust his advice and run a filter test to be sure.