I put another 2.5 gal Peak Blue DEF in the RAM yesterday using my theory of why they leak. The last two or three boxes I have put in did not leak, drip or have other issues. When you screw on the spout the little black duckbill vent ends up at the near side of the box(not the center of the box). So to use the box extend the spout and tip the box up with this vent of the high side(like upside down). The vent lets air in from the high side of the spout to replace the DEF exiting without leaking a drop. As the box empties it gets raised up to have the near side flat to the side of the truck.To say it another way, pour from the high side not the low side!Try it, you will like it.Chris

Ya know ya got it right when you hear that steady sucking sound!

A lot of containers are designed to be poured in not-so-obvious ways. Take your average everyday quart of oil, for example. It's meant to be poured with the neck to the high side. This allows you to have the bottle at almost a 90 degree angle to the funnel before any oil comes out, so it doesn't dribble down the side of the bottle. Common antifreeze jugs are meant to be poured on their sides for a similar reason.

Going to a DEF pump seems like an even more elegant solution for a lot of reasons.

My filling process for using the Peak DEF fluid is very simple utilizing these 3 simple steps.Step 1 Throw away the nozzle provided in the DEF boxStep 2 Connect my Ford Motorcraft DEF fluid nozzle and snap the nozzle to the DEF fill port.Step 3 Poor the DEF fluid until the fluid doesn't flow anymore. Which means the tank is full.The Ford Motorcraft nozzle is a excellent design that will not allow a over fill and spill condition and I never spill a drop.Link

Leaky Peak Blue DEF box solution! | Good Sam Community

Cummins12V98
Explorer III
Sep 25, 2018
Ya know ya got it right when you hear that steady sucking sound!
seminole39
Explorer
Sep 25, 2018
DEF? What is that?? ;)
mkirsch
Nomad II
Sep 25, 2018
A lot of containers are designed to be poured in not-so-obvious ways. Take your average everyday quart of oil, for example. It's meant to be poured with the neck to the high side. This allows you to have the bottle at almost a 90 degree angle to the funnel before any oil comes out, so it doesn't dribble down the side of the bottle. Common antifreeze jugs are meant to be poured on their sides for a similar reason.
IdaD
Explorer
Sep 25, 2018
Going to a DEF pump seems like an even more elegant solution for a lot of reasons.
FishOnOne
Nomad
Sep 25, 2018
My filling process for using the Peak DEF fluid is very simple utilizing these 3 simple steps.

Step 1 Throw away the nozzle provided in the DEF box
Step 2 Connect my Ford Motorcraft DEF fluid nozzle and snap the nozzle to the DEF fill port.
Step 3 Poor the DEF fluid until the fluid doesn't flow anymore. Which means the tank is full.

The Ford Motorcraft nozzle is a excellent design that will not allow a over fill and spill condition and I never spill a drop.

Link
Ron3rd
Explorer III
Sep 26, 2018
Just curious why people buy Peak instead of the Walmart brand. Same thing
Me_Again
Explorer III
Sep 26, 2018
If you get bad DEF, which one Walmart or Peak is going to step up to the plate and help you? 2 or 3 bucks over hundreds of miles is not a big deal.
Perrysburg_Dodg
Explorer
Sep 26, 2018
"Leaky Peak Blue DEF box solution" drive to a truck stop and fill up your DEF there, problem solved.

Don
Lynnmor
Explorer
Sep 26, 2018
Perrysburg Dodgeboy wrote:
"Leaky Peak Blue DEF box solution" drive to a truck stop and fill up your DEF there, problem solved.

Don

It would cost me more than $10 in fuel to drive to the nearest truck stop and their prices for DEF and fuel are higher than average. I buy at Walmart so I can fill when I want without taking special trips to a filthy pump.
harmanrk
Explorer
Sep 26, 2018
Lynnmor wrote:
It would cost me more than $10 in fuel to drive to the nearest truck stop and their prices for DEF and fuel are higher than average. I buy at Walmart so I can fill when I want without taking special trips to a filthy pump.

My guess is by the time you drive to the local Walmart, you've probably passed a truck stop, or are not too far away. Also with the DEF tank going 7500+ miles between fill ups, it not like a special trip is required to a truck stop, just stop at any you pass in a given month when it is getting low.

That said I have only used the Peak boxed DEF, and not had issues with leaking to any concerning extent. I think I have added 7.5 gallons in the 12 months I have owned the truck Setting at a quarter tank, so nearly time to add another jug or two.