DEF freezing

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Dec 8, 2014 | 06:41 PM

#16

Tom

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Joined: Aug 2003

Posts: 25,479

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From: Isanti, MN

Not sure why all the uncertainty with this system, all of this is covered in the diesel supplement.

Quote:

Originally Posted by 2011 Diesel Supplement P. 34-35

Filling the DEF tank in cold climates
DEF will freeze below 12°F (-11°C); however, your vehicle is equipped
with an automatic preheating system which allows the DEF system to
operate below 12°F (-11°C). When the vehicle is not in operation for an
extended period of time with temperatures at or below 12°F (-11°C), the
DEF tank could freeze. If the tank is OVERFILLED and freezes, it could
be damaged, therefore DO NOT OVERFILL.To prevent overfilling of the DEF tank when filling with a bottle, Ford
recommends using Motorcraft DEF. Additionally, if the message center
indicates EXHAUST FLUID UNDER 1/2 FULL, you should only add a
MAXIMUM of 2 gallons (6.7L) of DEF to the tank to prevent freeze
damage due to overfilling. If the message center indicates EXHAUST
FLUID LEVEL OK, do not add DEF.

There's no mystery here. Fill it when it gets low, and don't overdo it. That's all there is to it.

Dec 9, 2014 | 04:53 AM

#17

ct diesel

Posting Guru

Joined: Jul 2013

Posts: 1,726

Likes: 2

From: Connecticut

Quote:

Originally Posted by Tom

Not sure why all the uncertainty with this system, all of this is covered in the diesel supplement.

There's no mystery here. Fill it when it gets low, and don't overdo it. That's all there is to it.

Thanks Tom. I didn't see that when I read the diesel book. Makes a lot of sense.