Testing DEF

[Wayne M.]

Today, I had a chance to use two refractometers, and look at some known good DEF.
Some here know that I am a Mechanic in a the largest Municipal fleet in the country, and most of my work during the summer is getting our winter equipment ready for the next season. Since there is so much controversy with this DEF, and more and more equipment is using it, the management has required testing of what's in the tank of what I'm working on. They've only given us refractometers and I don't think they've given much thought about fuel contamination, I see there are dip test strips out for that.
In this case it's a brandy new '17 6.7 F550, and I believe this to still be the factory fill. The configuration of the truck allows an easy siphon of the fluid using a oil sample draw pump and kit.
I stuck my phone lens in the eyepiece, and got some okay shots to share what it looks like in there.
I used 2 refractometers. One I have for coolant and battery electrolyte, that reads specific gravity, and a dedicated OTC refractor that just reads DEF purity.

It's understood that pure DEF has a rating of 32.5% and while the specific gravity rating is a gray area, I found a reference of 1.315.
Here is the pure sample. Through the OTC tool.

Here is the same fluid through my other tool, showing 1.315 SG.

To experiment, and to compare what's being suggested on another thread, I diluted the DEF 50% with water cooler water. Here's the view.

I show 22.5%.

This next picture is what you see with straight water, and is a calibration reference.

I hope this encourages folks with SCR trucks to start testing their DEF fluid. These pro tools are not too expensive for the ultimate in gadgets, and there's a plethora of float type hydrometers out there as well.

 

[Bob4x4]

The problem with the test strips #1 is cost,because they are only sold in large quantity and #2 will not measure down to the level they start to degrade the system.They should be dipped directly in the tank(lower portion)not on a pumped out sample.

 

[Cummins2014]

Today, I had a chance to use two refractometers, and look at some known good DEF.
Some here know that I am a Mechanic in a the largest Municipal fleet in the country, and most of my work during the summer is getting our winter equipment ready for the next season. Since there is so much controversy with this DEF, and more and more equipment is using it, the management has required testing of what's in the tank of what I'm working on. They've only given us refractometers and I don't think they've given much thought about fuel contamination, I see there are dip test strips out for that.
In this case it's a brandy new '17 6.7 F550, and I believe this to still be the factory fill. The configuration of the truck allows an easy siphon of the fluid using a oil sample draw pump and kit.
I stuck my phone lens in the eyepiece, and got some okay shots to share what it looks like in there.
I used 2 refractometers. One I have for coolant and battery electrolyte, that reads specific gravity, and a dedicated OTC refractor that just reads DEF purity.

It's understood that pure DEF has a rating of 32.5% and while the specific gravity rating is a gray area, I found a reference of 1.315.
Here is the pure sample. Through the OTC tool.
View attachment 98716
Here is the same fluid through my other tool, showing 1.315 SG.
View attachment 98717

To experiment, and to compare what's being suggested on another thread, I diluted the DEF 50% with water cooler water. Here's the view.
View attachment 98718
I show 22.5%.

This next picture is what you see with straight water, and is a calibration reference.
View attachment 98719

I hope this encourages folks with SCR trucks to start testing their DEF fluid. These pro tools are not too expensive for the ultimate in gadgets, and there's a plethora of float type hydrometers out there as well.

I wish that was my issues, and by testing could prevent a problem with my DEF. My problems seem to be from the injector getting build up causing a " Service DEF See Dealer " They have tested my DEF on two occasions ,and it was good.

I understand the need for testing . I use Peak DEF, and just don't see how two month old or newer DEF is going to be bad, so far it has not in the three years I have used it .

 

[Wayne M.]

Hey it's possible to get a bad batch in a box. This stuff is quite sensitive regarding storage. I would test every box I open.
I had to do a whole tank to injector flush/ replace due to diesel contamination. Truck had no issue before, and the injector had a huge bloom on it, but it was clear around the pintle. This is a simple system. It needs a good spray of good reagent, and the sensor needs to see the right feedback.

 

[Cummins2014]

Hey it's possible to get a bad batch in a box. This stuff is quite sensitive regarding storage. I would test every box I open.
I had to do a whole tank to injector flush/ replace due to diesel contamination. Truck had no issue before, and the injector had a huge bloom on it, but it was clear around the pintle. This is a simple system. It needs a good spray of good reagent, and the sensor needs to see the right feedback.

I hear what you are saying, but as said bad DEF is not my issues. wish it was, then I could eliminate it by testing.

I also see what you are saying about storage, but right now a local retailer has some Peak DEF that I was looking at just yesterday that was just a month old. I just can't see where that DEF in a sealed cardboard box could have been exposed to enough heat or sunlight to have gone bad in a month. I guess its possible, just don't see how it could.

 

[Bob4x4]

FCA does not accept any flush after hydrocarbon contamination,system must be replaced.As far as def testing goes the injector flow rate and pattern should be done to verify system operation.Just testing with a refractometer is an inaccurate test.

 

[Wayne M.]

Just testing with a refractometer is an inaccurate test.

Yup I agree, so what else is there that can be done to prevent system disaster? What's FCA's approach in purity testing?

 

[Bob4x4]

Yup I agree, so what else is there that can be done to prevent system disaster? What's FCA's approach in purity testing?

LOL,dont put diesel in it..............

 

[Wayne M.]

I just got back from Mack Truck emissions training. I gotta say it seems they have a real good handle on their SCR management. Starting real recently, they even have a urea quality sensor in the tank that can calculate the number seen on the refractometer, on their scan tool. It was pretty interesting. They also have a Nox reporting test that runs the engine under certain conditions including shutdown and no start crank to purge the exhaust system. The end goal is to get zero at the sensors, and sweep them to max through the test. You can watch them in real time during the test. In the test description, some DTCs were listed to use this test for, and the famous P207F was there among others.
They reccomend a refractometer and oil detection test strips to check samples.

 

[jgillott]

LOL,dont put diesel in it..............

It's sad, but it happens more often than we may think. I've been talking to a MB tech recently about what he is seeing as far as DEF issues. Since the Sprinter DEF tank is under the hood, they are seeing window washer fluid, antifreeze, and believe it or not even gear oil being dumped in the tank. Apparently one owner mistook the DEF on the cap as to mean Differential and went to the parts store and asked for "Differential Fluid".

 

[Lynx0849]

It's sad, but it happens more often than we may think. I've been talking to a MB tech recently about what he is seeing as far as DEF issues. Since the Sprinter DEF tank is under the hood, they are seeing window washer fluid, antifreeze, and believe it or not even gear oil being dumped in the tank. Apparently one owner mistook the DEF on the cap as to mean Differential and went to the parts store and asked for "Differential Fluid".

Sigh... well we know how many men read the instruction manual