I've been driving vehicles using DEF for several years, what were Ford Truck and Mercedes so did not think much about adding DEF to my Discovery, when the warning come on.
Liked the warning, who would tell me remaining range and how much to add, but the refill was a total disaster.
1st I went to truck stop with DEF pumps. Turned out the DEF cap on Discovery require a wrench, who was not included in car set. It is 3/8" square,
Then I bought 2.5gallons jug at Costco and tried to refill it in the garage.
The hose, that come with jug was tight fit into the neck and would not allow for the air to bleed, so after filling some, I backed up the hose and the pressure that build inside the tank, burped DEF back, spilling it on the fender, inner fender, wheel, suspension and garage floor.
I slowly managed to pour the remaining DEF into the tank, but how you guys do it, without creating whole havoc around?

 

1. Park on an incline, front end uphill.
2. Get a DEF funnel or make one.

 

Oh, boy another tool I will have to spend money on and then seek it in my garage, when needed.
Anyone tried the truck stops pump for the job?
Thanks for links.

 

I've been pretty happy with this tool.
I usually just place the (costco/sams club) DEF container on the engine, pump once or twice and it turns into a siphon; wait a few mins and
No spills at all.

https://www.oreillyauto.com/detail/c...ump/pfm0/w1145
UPC: 39564112577 (in case the URL dies in future)

 

That hose will let the fluid overflow, if you don't keep your eye on it.
Did anyone research DEF tanks on Land Rovers?
Mercedes is using ultrasounds to measure DEF level and maintaining air gap on top is crucial for the gauge to work, or you open whole bucket of worms, including count down.
I wonder how critical it is on Discovery?

 

i hear over-filling DEF can also be quite problematic on D5. I've only refilled DEF once the gauge asks for 2.5+ gallon; that way I can empty the costco container without worrying about overfill.

 

My dilemma is that I prefer use of pumps ,where DEF is not only the cheapest ($2,99) but fresh and easy to fill (at least on my Mercedes).
I did not measure it, but hope pump nozzle is smaller and it will not create burps.
I don't drive D5 much, so it will take me few months to give it another try.
Another question for winter use, common issue on Sprinters was DEF heater, installed above the bottom and with low fluid level, it would get exposed and burn out in cold weather. Since on Sprinter the tank is sealed as whole unit, the heater failure is bringing $3000 bill.
Any experience with it on D5 ?

 

I recall seeing some technical diagrams of the DEF system. take a swing at searching the threads in the D5 forum.
respond back here if the search goes in vain.

 

I just buy enough bulk for my two diesel vehicles .

 

How do you avoid spills using big can? Do you worry about leaving air space on the top?