Def gauge.

GreyGoat

Tremor Member
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Location
Alpine, CA
Military
USN - RET
Current Ride
2020 F350 TREMOR
Def gauge always reads full. Anyone having this issue. I have heard about a lot of def related issues, but a gauge miss read WTF. Just put aBOUT 1.5 gallons in. About 700 miles since last fill up.
 
Its a pretty large tank, I don't keep mine topped off. In the freezing zone. So I will only add it when it tells me. It could freeze then expand and cause damage to the system. I don't see much usage of DEF when not towing or empty. BUT..... pull a heavy trailer or 5th wheel and you will use about 5 gallons for every 900 miles maybe more.
 
Its a pretty large tank, I don't keep mine topped off. In the freezing zone. So I will only add it when it tells me. It could freeze then expand and cause damage to the system. I don't see much usage of DEF when not towing or empty. BUT..... pull a heavy trailer or 5th wheel and you will use about 5 gallons for every 900 miles maybe more.
facts ... when empty don't use alot but when towing it will empty it in 5 hours
 
Def gauge always reads full. Anyone having this issue. I have heard about a lot of def related issues, but a gauge miss read WTF. Just put aBOUT 1.5 gallons in. About 700 miles since last fill up.
Same here, I had the dealership check it at my last oil change. Used very little, but all empty miles. I will be keeping an eye on it.
 
facts ... when empty don't use alot but when towing it will empty it in 5 hours
Have you noticed that too or am I just crazy?????
 
I went about 5000 miles and about 4 months on the original DEF tank fill from when I bought it.... The couple of times I've towed the DEF drain rate seems considerably faster since the truck is on boost more. I put 5 gals back in and I'm still at 3/4 full after an additional 1500 miles. I'm kinda wishing I would have just added 2.5 Gals since it will take months again to consume that fluid and by then the fluid is likely old and stale.

I've heard from a Diesel technician that it's not advisable to fill DEF tanks to full (especially with the Ford 7 Gal capacities) if you're not going to Tow loads that will drain the tank quickly. Essentially if your DEF tanks takes months to consume then it's best to just fill it to maybe half or less full so that the DEF fluid doesn't sit in your tank and possibly corrode things, freeze and expand in the cold climates or the fluid just goes plain stale.
 
I went about 5000 miles and about 4 months on the original DEF tank fill from when I bought it.... The couple of times I've towed the DEF drain rate seems considerably faster since the truck is on boost more. I put 5 gals back in and I'm still at 3/4 full after an additional 1500 miles. I'm kinda wishing I would have just added 2.5 Gals since it will take months again to consume that fluid and by then the fluid is likely old and stale.

I've heard from a Diesel technician that it's not advisable to fill DEF tanks to full (especially with the Ford 7 Gal capacities) if you're not going to Tow loads that will drain the tank quickly. Essentially if your DEF tanks takes months to consume then it's best to just fill it to maybe half or less full so that the DEF fluid doesn't sit in your tank and possibly corrode things, freeze and expand in the cold climates or the fluid just goes plain stale.
Yes to all of this. I plan to run mine till its low then add 2.5 gallon container.
In the summer when towing more I will go to the truck stop and just buy it at the pump so I can save a few bucks and will top it off before a long trip.

the DEF can freeze and its very corrosive lovey stuff thank you feds for coming up with this crap and all your regulations I feel like we are single handily saving the planet from global warming one Tremor at a Time.
 
I have run 5000 miles since I filled mine last....it still reads at least 3/8 full!
 
I went about 5000 miles and about 4 months on the original DEF tank fill from when I bought it.... The couple of times I've towed the DEF drain rate seems considerably faster since the truck is on boost more. I put 5 gals back in and I'm still at 3/4 full after an additional 1500 miles. I'm kinda wishing I would have just added 2.5 Gals since it will take months again to consume that fluid and by then the fluid is likely old and stale.

I've heard from a Diesel technician that it's not advisable to fill DEF tanks to full (especially with the Ford 7 Gal capacities) if you're not going to Tow loads that will drain the tank quickly. Essentially if your DEF tanks takes months to consume then it's best to just fill it to maybe half or less full so that the DEF fluid doesn't sit in your tank and possibly corrode things, freeze and expand in the cold climates or the fluid just goes plain stale.
pretty sure DEF doesn't go bad or corrode anything. Actually I'm 100% certain about that. It has no additives or preservatives so has no stated shelf life.
 
pretty sure DEF doesn't go bad or corrode anything. Actually I'm 100% certain about that. It has no additives or preservatives so has no stated shelf life.
well i been told otherwise and this suggests it does have a shelf life ... and can do bad as it gets cloudy

 
def does freeze but at 12 degrees so keep it warm above 12 degrees

3. Cold Concerns
DEF isn’t harmed by freezing, good news for those who live in colder climates. Because it’s 2/3 water, it begins to turn slushy at 12 degrees Fahrenheit and will freeze solid. One thing to keep in mind is DEF will expand when frozen, so it’s best not to fill containers completely full to avoid damage to them.

After it has been frozen, DEF can be thawed and used with no issues. Don’t add chemicals or additives in an effort to prevent freezing, as doing so may contaminate and ruin the fluid.
 
well i been told otherwise and this suggests it does have a shelf life ... and can do bad as it gets cloudy



interesting....I guess anything goes bad given enough time, but my read of that is you'd basically have to fill the DEF tank and then just stop driving the truck for a year. Practically speaking, it won't go bad. I guess the argument is don't order a bulk pallet of the stuff.
 
interesting....I guess anything goes bad given enough time, but my read of that is you'd basically have to fill the DEF tank and then just stop driving the truck for a year. Practically speaking, it won't go bad. I guess the argument is don't order a bulk pallet of the stuff.
Yea, I was looking I to doing that but because it does have a shelf life it cheaper and make more sense to just get it at the pump over buying the $50 box
 
Its a pretty large tank, I don't keep mine topped off. In the freezing zone. So I will only add it when it tells me. It could freeze then expand and cause damage to the system. I don't see much usage of DEF when not towing or empty. BUT..... pull a heavy trailer or 5th wheel and you will use about 5 gallons for every 900 miles maybe more.
I just has my 5K oil change on my 2020 F-350 6.7L. The dealer put 2.5 gal of DEF in. I was surprised as I had added 2.5 myself less than a month ago. The gauge now reads 2/3 full. I have towed my 3 horse trailer a total of 300 miles! Rather surprised as my previous SD didn't use anything close to that. I guess I need to pay attention to that.
 
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I just has my 5K oil change on my 2020 F-350 7.3L. The dealer put 2.5 gal of DEF in. I was surprised as I had added 2.5 myself less than a month ago. The gauge now reads 2/3 full. I have towed my 3 horse trailer a total of 300 miles! Rather surprised as my previous SD didn't use anything close to that. I guess I need to pay attention to that.
Your 7.3L takes DEF???
 
I just has my 5K oil change on my 2020 F-350 7.3L. The dealer put 2.5 gal of DEF in. I was surprised as I had added 2.5 myself less than a month ago. The gauge now reads 2/3 full. I have towed my 3 horse trailer a total of 300 miles! Rather surprised as my previous SD didn't use anything close to that. I guess I need to pay attention to that.
I hope the 7.3 isn't using DEF.
 
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