weird situation with gas filler tube on E450 2008 Tioga 31M and a blockage

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decaturbob

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Oct 31, 2015
Posts
532
Location
central Illinois
Went into panic mode when filling up where it appear to have a blockage in the fill tube which essentially I couldn't pump gas in except at a dribble rate. Luckily our destination was well within range of the gas I had in the tank.  So took a couple days to get set up and back to analyze what the heck is going on.  I got a small ryobi inspection camera and started probing the fill tube and definitely ran into an obstruction about 10-12 inches down from the gas cap location which I believed I dislodged with the fiber optic in the process.  I did have an electrician's snake which I carefully fed down the tube and didn't come into contact with anything for 30 inches.  So any one seen or heard of this? Does this gas fill tubes have some type of anti-syphon doohickey built in? Not leaving Lake Havasu City for another month to head back to central illinois and hate having to contend with this situation again.  BTW the ryobi inspection camera pretty nice, connects wirelessly to your smart phone for display, photos, video recordings
 
So you ran into an obstruction - with the camera - do you know what it looked like?

I do believe that there are baffles of some type in the tube.  Keeps one from sucking fuel out of the tank, and fuel from splashing backwards.

If you know for sure you dropped something into the tank - then your best course of action is going to be to drop the tank and check it out.
Unless you want to take the chance that your engine will stop while driving in traffic.

You might get lucky - IF you can just remove the filler tube - carefully - maybe what fell down didn't make it to the tank and is at the bottom of the tube yet. 
 
a snake and a camera down the filler tube. one spark and you can kiss it all good bye.
it is probably the air breather tube is kinked, blocked or full of fuel . if you can see the filler neck and hose from underneath there should be a smaller hose running running along with it. this is probably the culprit and straightening or if hanging with a sag, lift it so any fuel will run back into the tank then zip-ty it up so it stays straight .
 
beaverfever said:
a snake and a camera down the filler tube. one spark and you can kiss it all good bye.
it is probably the air breather tube is kinked, blocked or full of fuel . if you can see the filler neck and hose from underneath there should be a smaller hose running running along with it. this is probably the culprit and straightening or if hanging with a sag, lift it so any fuel will run back into the tank then zip-ty it up so it stays straight .

not worried about a 4.5vdc camera initiating any spark or a rubber tipped electrical snake.  I'll look under RV in morning
 
This reminds me of an issue I had with a 2007 Nissan Pathfinder sold in California, where I would have trouble pumping gas. The issue that this particular vehicle had, and I learned, many other makes also suffer from, is a clogged charcoal canister and evaporation release valve. The valve is supposed to close in order to prevent fumes from the tank from escaping into the atmosphere.  I think it was for California emission standards.  When the valve goes bad or the canister is full, it shuts off, preventing any fuel from going into the tank. I don't know whether Ford's also have this canister and release valve, but is something to consider.
 
cgmartin said:
This reminds me of an issue I had with a 2007 Nissan Pathfinder sold in California, where I would have trouble pumping gas. The issue that this particular vehicle had, and I learned, many other makes also suffer from, is a clogged charcoal canister and evaporation release valve. The valve is supposed to close in order to prevent fumes from the tank from escaping into the atmosphere.  I think it was for California emission standards.  When the valve goes bad or the canister is full, it shuts off, preventing any fuel from going into the tank. I don't know whether Ford's also have this canister and release valve, but is something to consider.

I'm pretty sure the issue is related to the venting of the tank and its a hit or miss problem.  One time I can fill up with no problem and another time I'm lucky to get 5 gallons of gas in the tank, its made driving back 1800 miles very interesting at the least.  I'm still close to 500 miles away from home and need to fill up twice more to get home so then I can look at the Ford tank and the venting system.  Something is definitely preventing gas from going down the filler tube into the tank and a plug vent could very well be the problem.
 
apparently gas tank venting has been an issue with ford super duty vehicles for years as what I gather from researching.  I'm just hoping to get home today so i can look into this closer.  Issues arise from kinked or clogged vent hoses to clogged charcoal canisters.
 
decaturbob said:
Went into panic mode when filling up where it appear to have a blockage in the fill tube which essentially I couldn't pump gas in except at a dribble rate. Luckily our destination was well within range of the gas I had in the tank. 

decaturbob
A sag or droop in the fuel tank vent line can/will cause that... because fuel in the sag/droop prevents the air in the tank being displaced by the incoming fuel from exiting the tank, (similar to how a p-trap works).
If the air in the tank can't escape through the vent hose it forces the incoming fuel back up the fill tube/hose...shutting off the pump.
I was able pull the sag out of my vent hose and cut it 5" shorter, thereby eliminating the sag and fixing the slow fill problem.
 
mel s said:
decaturbob
A sag or droop in the fuel tank vent line can/will cause that... because fuel in the sag/droop prevents the air in the tank being displaced by the incoming fuel from exiting the tank, (similar to how a p-trap works).
If the air in the tank can't escape through the vent hose it forces the incoming fuel back up the fill tube/hose...shutting off the pump.
I was able pull the sag out of my vent hose and cut it 5" shorter, thereby eliminating the sag and fixing the slow fill problem.

the issue with my situation with filling the tank is the failure comes and goes and is not a consistent problem, I am going to check the vent lines out for sure as there appears to be 2 of them that run externally along the side of the filler tube to the tank. 
 
???only in an RV would a straight tube to a tank get screwed up!! :mad: :mad:    It's not even far!

Do you store the vehicle where someone could have put something in the tube that is rattling around??
 
decaturbob said:
not worried about a 4.5vdc camera initiating any spark or a rubber tipped electrical snake.

I know,.... years ago I watched a guy bet someone $100 he could put out a lit cigarette in his motorcycle gas tank......he won and we all laughed.
 
I don't want to hijack decaturbob's post, but the short explanation is that, because of my wife's health, we still had our original tank of gas, even though we've had the MH for over a year.  Over its 25 year life, the MH had an extra tank installed, and I believe the gas gauge is connected to only one tank.  I assumed it was connected to the original factory tank, but it looks like it's connected to the newer, bigger tank.  Anyway, the gauge read empty, and I could only fit 7 gallons in the original tank.  So I spent a lot of time yesterday shaking the vent pipe, and it still wouldn't take any more gas.  I finally tried the other tank and it took 26 gallons.  So my problem isn't anything like decaturbob's!  I just don't know what I'm doing.
 
KandT said:
???only in an RV would a straight tube to a tank get screwed up!! :mad: :mad:    It's not even far!

Do you store the vehicle where someone could have put something in the tube that is rattling around??

Im thinking the vent tubes and I have 2 running up along side the filler tube has something plugging.  I have a can of compressed air with me now to check when I have the problem next time.
 
Did the air cannister blow out whatever was in the vent?  My 07 31M has this slow gas issue and it seems to have gotten worse the last year (or I've gotten less patient with it).  I'm going to call Fleetwood tomorrow to see if they can send me the schematics for the gas line and their mods to it. I suspect my hose from the tank isn't level and I may need to get a hanger on it.
 
Perick said:
Did the air cannister blow out whatever was in the vent?  My 07 31M has this slow gas issue and it seems to have gotten worse the last year (or I've gotten less patient with it).  I'm going to call Fleetwood tomorrow to see if they can send me the schematics for the gas line and their mods to it. I suspect my hose from the tank isn't level and I may need to get a hanger on it.

the mystery remains unsolved and comes and goes.  In last 3,000 miles of driving, I have had one or 2 problematic fillups. To solve, most likely will require dropping the tank and that is something I would have to pay a commercial truck shop to do.  I make it point to fill up when I get to 1/2 tank.
 
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