Filling (DEF) Diesel Exhaust Fluid Tank without Overflow

calemasters

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When filling the DEF tank, is there a way to know when the tank is nearing "full" so that the DEF does not overflow from the filler tube? I have yet to find an indicator (DEF tank gage excluded because I can not see the gage when filling and the gage is dampened).

So how do you know when the tank is full prior to the overflow?
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BDinTX

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Can't answer your question directly but with my truck I put in 1 new jug of DEF when I get slightly below 1/2 tank. It may not be 100% full but it all goes in rather than all over the ground.
 

CWRUYOTE

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Slightly off-topic, but if you go to a truck stop that has DEF pumps, the DEF pump should automatically stop, similar to a fuel pump.

IIRC, the total volume of the DEF tank = 5.1 gals.
 
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calemasters

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Slightly off-topic, but if you go to a truck stop that has DEF pumps, the DEF pump should automatically stop, similar to a fuel pump.

IIRC, the total volume of the DEF tank = 5.1 gals.
I thought about that. It is actually a good suggestion. Also, there may be some cost savings as well. Thanks. :)
 

brewski

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Can't answer your question directly but with my truck I put in 1 new jug of DEF when I get slightly below 1/2 tank. It may not be 100% full but it all goes in rather than all over the ground.
@calemasters this is what I do. It is easy and never leads to an issue. DEF fluid is water based and therefore will go bad if you have it in your tank too long. So I'm not usually too worried about completely filling my DEF tank unless going on a long trip. Once a little below 1/2tank then I'll fill up w/ one box.

As far as DEF at the pumps, you need to be cautious with this because you don't know the age of the fluid in the tank. I only buy the boxes because then I know it is good. If there is a station near you and you know their DEF pump gets a lot of use then I wouldn't be concerned about pump DEF.
 

No Spark V6

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Can't answer your question directly but with my truck I put in 1 new jug of DEF when I get slightly below 1/2 tank. It may not be 100% full but it all goes in rather than all over the ground.
This is what I've been doing, but waiting for 1/4 tank. Just recently I was on a longer trip and I stopped at a truck stop to fill up. It is nice to have a full def tank without any spilling.
 
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calemasters

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@calemasters this is what I do. It is easy and never leads to an issue. DEF fluid is water based and therefore will go bad if you have it in your tank too long. So I'm not usually too worried about completely filling my DEF tank unless going on a long trip. Once a little below 1/2tank then I'll fill up w/ one box.

As far as DEF at the pumps, you need to be cautious with this because you don't know the age of the fluid in the tank. I only buy the boxes because then I know it is good. If there is a station near you and you know their DEF pump gets a lot of use then I wouldn't be concerned about pump DEF.
I would think that a busy truck stop would sell a large volume of DEF so it would be fairly fresh.
 

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Can't answer your question directly but with my truck I put in 1 new jug of DEF when I get slightly below 1/2 tank. It may not be 100% full but it all goes in rather than all over the ground.
This is the way!
 

brewski

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I would think that a busy truck stop would sell a large volume of DEF so it would be fairly fresh.
Maybe, but DEF system needs "clean" DE Fluid. It does not like foreign substances being mixed into the system. So there are also questions on if the tank clean? Is nozzle clean from contaminants? But if you're not going to keep the jeep for a long time, these would be things that may never affect you.
While I would 100% agree a busy truck stop is probably a safe option for pump DEF, I personally just buy the boxes and go that route to keep all that diesel exhaust system running the way it was intended and prevent the introduction issues from me trying to save a couple bucks here and there. A diesel engine is pretty simple and robust, but on a modern diesel everything after the turbo is quite a bit of finicky complications.
I also don't see a need to have a full DEF tank unless I'm on a 2000+ mile road trip.
 
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calemasters

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Maybe, but DEF system needs "clean" DE Fluid. It does not like foreign substances being mixed into the system. So there are also questions on if the tank clean? Is nozzle clean from contaminants? But if you're not going to keep the jeep for a long time, these would be things that may never affect you.
While I would 100% agree a busy truck stop is probably a safe option for pump DEF, I personally just buy the boxes and go that route to keep all that diesel exhaust system running the way it was intended and prevent the introduction issues from me trying to save a couple bucks here and there. A diesel engine is pretty simple and robust, but on a modern diesel everything after the turbo is quite a bit of finicky complications.
I also don't see a need to have a full DEF tank unless I'm on a 2000+ mile road trip.
A month ago, we did a 5,500 mile round trip to Redondo Beach, Ca. I left home with the DEF tank at 100%. I was under the impression that a full 5.1 gallon DEF tank was good for approximately 10,000 miles. Wrong! On our return trip back home, while we were in Sedona, with 4,200 miles on the trip odometer, the DEF tank was at 15% remaining. Stopped at a Chevron and added 2.5 gallons of DEF to complete our trip. I am not sure how many miles you get from a full DEF tank, but it is not 10,000 miles.
 

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Maybe, but DEF system needs "clean" DE Fluid. It does not like foreign substances being mixed into the system. So there are also questions on if the tank clean? Is nozzle clean from contaminants? But if you're not going to keep the jeep for a long time, these would be things that may never affect you.
While I would 100% agree a busy truck stop is probably a safe option for pump DEF, I personally just buy the boxes and go that route to keep all that diesel exhaust system running the way it was intended and prevent the introduction issues from me trying to save a couple bucks here and there. A diesel engine is pretty simple and robust, but on a modern diesel everything after the turbo is quite a bit of finicky complications.
I also don't see a need to have a full DEF tank unless I'm on a 2000+ mile road trip.
You're certainly correct that DEF tanks and nozzles may not be properly maintained. But when buying the DEF boxes, you have no idea what happened between the manufacturing plant and the store shelf. That lot of boxed DEF may have been exposed to high temperatures in the warehouse, which would decrease its lifespan even shorter than its expiration date on the box.

It's just a balance of risk folks have to weigh for themselves.
 

brewski

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You're certainly correct that DEF tanks and nozzles may not be properly maintained. But when buying the DEF boxes, you have no idea what happened between the manufacturing plant and the store shelf. That lot of boxed DEF may have been exposed to high temperatures in the warehouse, which would decrease its lifespan even shorter than its expiration date on the box.

It's just a balance of risk folks have to weigh for themselves.
Excellent point


A month ago, we did a 5,500 mile round trip to Redondo Beach, Ca. I left home with the DEF tank at 100%. I was under the impression that a full 5.1 gallon DEF tank was good for approximately 10,000 miles. Wrong! On our return trip back home, while we were in Sedona, with 4,200 miles on the trip odometer, the DEF tank was at 15% remaining. Stopped at a Chevron and added 2.5 gallons of DEF to complete our trip. I am not sure how many miles you get from a full DEF tank, but it is not 10,000 miles.
Wow that seems low. The 10k per 5gal sounds really optimistic, typically you'll use about a gallon of DEF for every 1.0k-1.2k miles depending on how much load you put on the engine. So doing a lot of mountain passes versus driving thru Nebraska will result in different levels. Towing a light weight trailer I get around 5000 miles draining my DEF tank to 20%, but I haven't got a ton of miles on my Wrangler yet so maybe it will change with time. I do drive my wrangler slow, rarely go over 70mph and don't accelerate hard.
 

JbuckTN

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Mine just turned 5,000 miles and I have consumes 5 Gallons. 1K miles a gallon was spot on for me.
 
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