2015 Filler neck check flappers

[srd357]

I got a 2015 Ram Cummins last summer with a plow. Last fall I wanted to siphon some diesel from the tank. Well, not knowing that there are 2 check flappers, I got the siphon hose stuck in the 2nd flapper. I had to bust it out of the way to get my hose out. The flapper is sitting in the filler neck, and I will need to remove it or reinstall it. This truck just went up and down my driveway, plowing, a few times this winter, no other driving. I notice that my check engine light is on. Do you think that this removed flapper has caused the check engine light to come on? Any idea on how I can find out what's causing the check engine light to come on?

Thank you for your insight.

 

[SnoKing]

In the future, run a long screw driver down and push the flapper(s) aside.

You need to read the code(s) that set the check engine light. Most auto parts stores will do that for you.

 

[Newsa]

You can thread the siphon hose through a clean funnel. The funnel will open both flappers.

If the system detects the fuel tank is not sealed, it might trigger a CEL

 

[SnoKing]

You can thread the siphon hose through a clean funnel. The funnel will open both flappers.

If the system detects the fuel tank is not sealed, it might trigger a CEL

Those flaps do not appear to much of a seal!!!!

 

[Bob4x4]

The fuel tank (seal) is not monitored

 

[LandShark]

You can thread the siphon hose through a clean funnel. The funnel will open both flappers.

If the system detects the fuel tank is not sealed, it might trigger a CEL

There should be a funnel that came with the truck that is stored under the passenger seat, near the jack.

 

[Memflash]

Those flappers do a great job of sealing the tank. I have a 109 gallon auxiliary tank in the bed of my '17 3500 dually. A while back when I was filling both my stock and auxillary tanks I finished and went inside. When I came out fuel was running out from under the truck below the filler on the bed. I shut off the valve on the bed tank and it stopped. After some looking and checking I found a small round magnet had wedged between the lower flapper and seal. I got it out and that fixed the problem. While experimenting and trying different cures for my leak. I found that lower seal does a great job of sealing the system. Without it my top tank woul empty itself on the ground.

 

[Newsa]

Those flappers do a great job of sealing the tank. I have a 109 gallon auxiliary tank in the bed of my '17 3500 dually. A while back when I was filling both my stock and auxillary tanks I finished and went inside. When I came out fuel was running out from under the truck below the filler on the bed. I shut off the valve on the bed tank and it stopped. After some looking and checking I found a small round magnet had wedged between the lower flapper and seal. I got it out and that fixed the problem. While experimenting and trying different cures for my leak. I found that lower seal does a great job of sealing the system. Without it my top tank woul empty itself on the ground.

The weight of the fuel in the bed tank adds additional force on the bottom (tank side) of the flapper. Depending on the quality of the seal material will determine how long it lasts

 

[Memflash]

The weight of the fuel in the bed tank adds additional force on the bottom (tank side) of the flapper. Depending on the quality of the seal material will determine how long it lasts

The weight of the fuel in the tank doesn't affect the flapper. For example If you have a thousand gallons of fuel, water, any liquid, weighing say 7,000 lbs. up on a stand and you had a 1/2" hose or any other small size connected to the bottom you could hold that pressure back with a finger over the end. It's not cumulative.
When I was checking my seals I used a screwdriver to open both flappers and the fuel came up the neck but very slowly. I wanted to watch to make sure the valve didn't have any problems because of the magnet I had found wedged in the seal.
I just got back from a West coast swing this morning and my brain may be a little fried but I'm pretty sure on this.
Not trying to start a thing just don't want someone to think they will be sprayed with fuel if they open the flappers to have a look. One note of caution. In warm weather and if you just fueled I guess there could be some pressure from expansion.

 

[Newsa]

The weight of the fuel in the tank doesn't affect the flapper. For example If you have a thousand gallons of fuel, water, any liquid, weighing say 7,000 lbs. up on a stand and you had a 1/2" hose or any other small size connected to the bottom you could hold that pressure back with a finger over the end. It's not cumulative.
When I was checking my seals I used a screwdriver to open both flappers and the fuel came up the neck but very slowly. I wanted to watch to make sure the valve didn't have any problems because of the magnet I had found wedged in the seal.
I just got back from a West coast swing this morning and my brain may be a little fried but I'm pretty sure on this.
Not trying to start a thing just don't want someone to think they will be sprayed with fuel if they open the flappers to have a look. One note of caution. In warm weather and if you just fueled I guess there could be some pressure from expansion.

Actually, it is the height of the fluid in the axillary tank that pushes against the bottom flspper. If none of the fuel in the bed tank is above the flapper, then no additional force would be applied. Instead of mm of Hg, it would be mm of diesel.

I was mistaken in how I phrased it.

 

[JR]

mm hg? Huh?

 

[Jared Herzog]

Yeah. The pressure from the auxiliary tank is pretty dang close to zero so it is measured using something other than psi. I am not sure what it is. But, i have a 2500 gallon tank on my well. It is close to 8’ tall. At the base i have less than 2 psi of pressure. If i wanted to have pressure for my house without a booster pump that tank would be about 65’ in the air just so the appliances would have the required 42 psi minimum to function. Gravity could cause all the fuel to end up on the ground but it would not do it with much pressure

 

[Minnow101]

How does a magnet get introduced into the fill pipe and then migrate down the filler tube to the 2nd flap?

 

[Jared Herzog]

How does a magnet get introduced into the fill pipe and then migrate down the filler tube to the 2nd flap?

My billet diesel cap has a magnet. Wonder if his magnet came from some sort of fuel cap?

 

[Memflash]

I think the magnet came from the fuel pump nozzle. I don't know if it was some part of the nozzle but I doubt it. I was at a large truck stop and who knows what the nozzle could have come in contact with when it's used by hundreds of people a week. I do remember it was difficult to get truck to take fuel through the filler on the truck that time. I admit I gave the nozzle a pretty hard slam into the filler tube. It took the fuel after that. I may have knocked the magnet loose from the nozzle. All I care is that the magnet didn't come from my truck. My billet fuel cap is aluminum and has the magnet inside somewhere. As for getting to the second seal or flapper, when you fuel, the nozzle comes in contact with the second seal. It's only a couple or three inches down the tube from the first.
I'm confident it was part of the nozzle. I've made a trip through the northwest and another to west Texas and had no problems.

 

[6V92TA]

Actually, it is the height of the fluid in the axillary tank that pushes against the bottom flspper. If none of the fuel in the bed tank is above the flapper, then no additional force would be applied. Instead of mm of Hg, it would be mm of diesel.

I was mistaken in how I phrased it.

liquid seeks it own level, you just explained why.


30in Hg. I like that... its like one bar.. or 100kpa, or 14.7 psi..