# Diesel Exhaust Fluid per DIN 70070 & ISO 22241



## Doug Huffman (Apr 25, 2015)

Reading the standards literature for DEF, I see requirements for passenger car filling that BMW may not be meeting, depending on by what standards they're bound and here in the US.

Particularly in DIN 70070 I saw a zero spillage requirement. Trying to dig deeper, the documents are closely held and require purchase to read them in their entirety. ISO 22241, for instance, costs CHF 88.00 per section even as a PDF.

*If a correspondent here has a link URL to a publicly accessible copy of DIN 70070 or ISO 22241.5*, I would appreciate it, even by PM.

My interest is piqued by my DEF refill at the dealer that left the engine compartment a mess for spillage, and the SA statement that the operation was done with a hose-pump-tank rig. I suspect that the DEF tank failures may be related to the overpressure caused by dynamic impulse - water hammer - on the tank going full. Also the operational vent filter may become clogged by repeated wetting and fail to vent the tank which then collapses under vacuum while in service.


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## KeithS (Dec 30, 2001)

Not sure why there is a zero spillage requirement, DEF is essentially fertilizer or cow urine. It's dumped on the ground in massive quantities all over the world. In regards to overfilling and damaging the DEF tanks using a pump, I do not think this is the issue. The tanks themselves are not failing, it's all the sensors and other electronic components in them that fail. The part about causing the vent to plug is true, but can happen by overfilling just using the gravity method. I recall one post from a person wondering why all this DEF was on the ground when he put 2.5 gallons into the active tank. 

Right now I have no DEF filling issues because the car is not asking for any, for the past 23K miles. My SES just went on but for a NOx sensor #1 circuit intermittent. I suspect I will be getting the major tank replacement/overhaul, but we will see when I bring it in next week. Car runs perfectly, MPG is right where it should be.


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## Doug Huffman (Apr 25, 2015)

KeithS said:


> Not sure why there is a zero spillage requirement, ... , but can happen by overfilling just using the gravity method. [ ... ]


Is gravity fill - not bottle fill - recommended by either DIN or ISO standard?


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## KeithS (Dec 30, 2001)

Doug Huffman said:


> Is gravity fill - not bottle fill - recommended by either DIN or ISO standard?


I have no idea. I believe in the example I used the poster squeezed the DEF bottle to force the fluid in.


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## montr (Oct 7, 2006)

Here is the DEF refill system from BMW


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