Fuel tank splash-back issue that has me baffled!

[124XL]

Thanks in advance for any help or suggestions you may have – I greatly appreciate it! I searched through all the threads I could find to try to figure this out on my own, but wasn’t able to find an answer that solved my issue, so I’m starting this new thread.

I have a 2010 Ram 1500 Quad 4x4 5.7L w/32gal tank (and less than 60k miles). About a year ago, it started splashing back fuel when I filled it up. I did some research online and found that the only apparent fix was to replace the fuel tank. Not wanting to spend that much money, I learned to live with it. At first, if I filled up at stations with slow pumps, or if I filled up more often (pumping less gallons of fuel), I could sometimes get away without it happening. However, it’s continued to get worse, to the point that it happens all the time.

In general, almost everything I’ve read stated that it’s a known problem on numerous different Chrysler products, stemming from the rollover valve in the tank. Because the valve isn’t serviceable, the tank has to be replaced. Digging deeper, though, I found some posts (mostly pertaining to slow fill-ups as opposed to splash-backs) that lead me to believe it could possibly be something else.

So, here’s what I’ve tried so far…

1) I unplugged the Fuel Vapor Re-Circulation Tube from Vent Tube on the Fuel Filler Tube assembly (where you pump fuel into). The Fuel Vapor Re-Circulation Tube goes from the Vent Tube on the Fuel Filler Tube assembly to the top of the fuel tank and connects to a nipple (my understanding, the nipple on the roll-over valve). Leaving the Fuel Vapor Re-Circulation Tube connected to the valve, I can suck (and blow) air in and out of the fuel tank via the Fuel Vapor Re-Circulation Tube without issue. In fact, I can hear the valve opening and closing when I do it, so I don’t believe that valve is stuck/at fault.

2) While the Fuel Vapor Re-Circulation Tube was disconnected from the Vent Tube on the Fuel Filler Tube assembly, I blew air back through the Vent Tube – nothing plugged there.

3) I unplugged the large rubber Clean Air Hose Line from the Leak Detection Pump Filter assembly (which is located just underneath/along side of the Fuel Filler Tube assembly). The Clean Air Hose Line connects the Leak Detection Pump Filter assembly to the Evaporative System Integrity Module Detector, found on the backside of the evaporative emissions Vapor Canister. I blew air through the Leak Detection Pump Filter assembly, as another member said (with the slow fill-up issue) that doing that fixed his issue. Although some dust blew out the top of the assembly, it was far from being plugged.

There are no known pinched hoses or lines, and nothing I checked above fixed the issue, so I’m really scratching my head here. If there are any technicians or any owners that have had similar experiences and have fixed the issue, I’d greatly appreciate any feedback.

Thanks so much!

 

[Tach_tech]

Basically you need to check for flow through every part of the vapour recirculating circuit. The vent line from tank to filler tube. The line from tank to canister. ESIM vent tube and filter. The canister could be clogged as well. Most common issue is that filter being plugged. You can try disconnecting each component then going to fill up with gas to see if it changes.

If all else fails then it’s likely a tank issue.

 

[124XL]

Basically you need to check for flow through every part of the vapour recirculating circuit. The vent line from tank to filler tube. The line from tank to canister. ESIM vent tube and filter. The canister could be clogged as well. Most common issue is that filter being plugged. You can try disconnecting each component then going to fill up with gas to see if it changes.

If all else fails then it’s likely a tank issue.

Thanks for the response. When you mentioned "Most common issue is that filter being plugged.", were you referring to the carbon canister? Or, were you talking about the Leak Detection Pump Filter (mentioned in my original post in step #3, that seems to be OK)? It's hard to get at some of the fittings on top of the tank without dropping the tank down, and with "Safer at Home" rules, I'm finding it hard to get miles on the truck, so doing one thing at a time is tough.

 

[Tach_tech]

Thanks for the response. When you mentioned "Most common issue is that filter being plugged.", were you referring to the carbon canister? Or, were you talking about the Leak Detection Pump Filter (mentioned in my original post in step #3, that seems to be OK)? It's hard to get at some of the fittings on top of the tank without dropping the tank down, and with "Safer at Home" rules, I'm finding it hard to get miles on the truck, so doing one thing at a time is tough.

The leak detector filter is the one I’m referring too.

 

[124XL]

I had found on another forum where a tech had installed a separate vent line (see his post/notes below), so I felt optimistic that that might work for me:

"I just worked on a 2010 dodge ram 1500. we found the either the check valve on the top of the tank was sticking or the evap canister was slowing down air to cause the restriction. either way I had come up with an answer to fix the problem and it works because we just put twenty gallons as fast as we could put it in at the gas station. we first pulled down the tank and checked all hoses for plugging or kinks. there were none. next checked the flapper. working great. finally i whipped off the fill neck and blew on the tank. it created air pressure that wouldn't vent. well it did vent but very slowly. so to fix the problem by installing a new vent line into the plastic tank just above and to the right of the fill tube. drilled and tapped a 3/8 pip fitting to a 5/16 nipple. put silicone on and around the threads. removed the recirculating line and plugged it on the tank and run the new vent line next to the filler tube and plugged into the old recirculating line coming from the filler neck by the cap. hope this helps."

Unfortunately, that hasn't worked either, so now I'm even more confused than before! (See attached photos of my tank after trying the new recirculating vent line.)

After installing the custom 1/4" ID recirculating vent hose and fitting, I reinstalled the tank and slowly put 31 gallons in. The nozzle clicked off, and some fuel - albeit, not a lot - splashed back. I was somewhat optimistic, but still worried. The next time I filled up, the "normal" amount splashed back. The next tank, wondering if maybe the vent hole in the fuel filler neck assembly was still partially plugged (even though I could blow through it w/compressed air), I unplugged the new custom recirculating vent line from the fuel filler neck fitting and filled the fuel tank that way. Not a good idea...the tank filled and just as the nozzle clicked off (splashing back), fuel came pouring out the new recirculating vent line I had unplugged, all over the ground (probably a quart worth or more). So, I'm struggling to wrap my head around how I could still be seeing this issue with a new free-flowing recirculating vent line in the tank?

 

[Dave2018]

I don't know if this might help, but there was a new filler neck that was offered in the early year trucks that changed the angle of the fill tube. It was mainly to help with difficulty in removing the pump nozzle but it might also help with splash back.

https://www.ramforum.com/threads/fuel-overflow-at-end-of-filling-up.100091/#post-1796240

This was a 2011 truck. Might be worth a look.

 

[124XL]

Thanks for the reply, Dave2018, I appreciate it and any other feedback. I only wonder why, if it was an issue with the angle of the tube, it started recently splashing back? I would have thought that it would have been an issue from day one? Who knows. I'm going through a patch right now where I don't have a bunch of extra money to throw parts at the truck, so I'm really trying to be diligent with this.

 

[Tach_tech]

Did you ever try leaving the ESIM filter unplugged and filling the tank?

 

[124XL]

Did you ever try leaving the ESIM filter unplugged and filling the tank?

Good morning, and thanks again for your reply. Yes; I unplugged the Clean Air Hose Line (that connects the Leak Detection Pump Filter assembly to the Evaporative System Integrity Module Detector on the back side of the evaporative canister) and filled the tank. Same problem. In fact, it splashed back three times - once about 1/2 gallon into a 23gal fill (with nozzle set on low); another time about 2 gallons in (with nozzle set on low); and finally when the tank was full (at that point, I was running the nozzle by hand, at a speed lower than the low setting on the nozzle).