DEF won't fill
Mountain Pass
Joined: Mar 2009
Posts: 191
Likes: 60
From: Ca Wine country
A Borescope is worth saving for. I've had one for 20 years fixing Turbines and I decided to stick it down my filler neck and look at the inside of my diesel tank for any shiny parts in there. I'll see if my Nikon will couple and send some pics for giggles.
Oh it was 6k 20 years ago with no video, optics are excellent for even now. Thinner the better on the guide tube if your thinking of getting one.
Oh it was 6k 20 years ago with no video, optics are excellent for even now. Thinner the better on the guide tube if your thinking of getting one.
Fleet Mechanic
Joined: Mar 2012
Posts: 1,738
Likes: 7
From: Land of the Free
A Borescope is worth saving for. I've had one for 20 years fixing Turbines and I decided to stick it down my filler neck and look at the inside of my diesel tank for any shiny parts in there. I'll see if my Nikon will couple and send some pics for giggles.
Oh it was 6k 20 years ago with no video, optics are excellent for even now. Thinner the better on the guide tube if your thinking of getting one.
Oh it was 6k 20 years ago with no video, optics are excellent for even now. Thinner the better on the guide tube if your thinking of getting one.
New User
Joined: Oct 2012
Posts: 2
Likes: 0
From: Toronto, Canada
Fixed
Hey guys, I figured out the problem. There is a small hose above the main DEF filler hose. I rubbed all of the dirt off of it with my fingers and that was it. She poured in no problem.
Obviously the hose above is for air. It was really dirty. I keep my truck fairly clean but have never cleaned under there before. Hopefully the dirt can't make its way into urea reservoir too easily.
Sorry it took me a week to post answer
Obviously the hose above is for air. It was really dirty. I keep my truck fairly clean but have never cleaned under there before. Hopefully the dirt can't make its way into urea reservoir too easily.
Sorry it took me a week to post answer
Worked like a charm. Thanks muchly.
Prolocutor
Joined: Jan 2009
Posts: 13,618
Likes: 1,247
From: Western MA
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
Post Fiend
Joined: Mar 2013
Posts: 5,929
Likes: 287
From: EC Iowa
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Hotshot
Joined: Nov 2000
Posts: 11,591
Likes: 14
From: Pflugerville, tx
the crank TRIES to turn with the starter.
need room in the shop!.. 69 chevy longbed with an LM7 EFI motor & trans, dropped and on airbags, disc brakes all around, cab chopped, windshield layed back. floor pans replaced. just have to get motivated to get back to welding and grinding.. can we go FWing instead!?!
29 ford sedan, custom chassis, needs finish welded, still gotta get the dropped axle and split wishbone. rebuild the 322 nailhead engine and 700-r4 tranny to go in it. got the 9in rear already.
and of course the 56 ford big window truck, with the LM7 engine and trans, need to finish the dash repair, then prep for paint, so I can put the new wiring harness in and the power windows..
did I mention the FW and dually are calling my name?!
New User
Joined: May 2017
Posts: 4
Likes: 0
def filler
My 2016 F 250 super duty 6.7L is doing the same thing. It will run in a little then overflow like it is full. I can hear it trickeling into the tank and the neck will slowly go down but it would take 5 hours to put in 2.5 gallons
6.7 Weight Loss
Joined: Jun 2017
Posts: 1,141
Likes: 5
From: Woodbury CT
Are you using the Ford filler tube PM-27-N and lining the arrow up with the back of the jug? It’s a PIA but using the Ford filler tube and squeezing the jug, then backing it out to allow air into the jug works for me.
Hotshot
Joined: Jul 2005
Posts: 13,834
Likes: 26
From: Middle Tn.
Very entertaining guys here haha.
To get back to the situation tho, I hope this is not a problem for all of us. As the DEF fluid goes down the DEF tank will be sucking in air through that small hose. If there is dirt on the end it will be sucking dirt into the DEF tank! We may need to put a little cap on there, right?
To get back to the situation tho, I hope this is not a problem for all of us. As the DEF fluid goes down the DEF tank will be sucking in air through that small hose. If there is dirt on the end it will be sucking dirt into the DEF tank! We may need to put a little cap on there, right?
6.7 Weight Loss
Joined: Jun 2017
Posts: 1,141
Likes: 5
From: Woodbury CT
My filler tube is ‘like new’, there is no way this thing is blocked and I cannot get the air to go into the jug. As posted above, I need to squeeze the jug, when I can no longer squeeze the thing I need to back it out a bit and let air back into the jug. Maybe I’m doing something wrong but following this process I can get 2 jugs into the tank when I get the 500 mile warning.
