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Fuel tank issue/question. Anyone with experience?

fignewton

Full Member
Joined
Sep 23, 2019
Messages
80
See my latest “what did you do” thread for background yesterday. I am having the fuel fill cutoff problem. Lines are clear, purge solenoid and vent solenoid working properly. Brand new charcoal canister. This morning, I went back under to check the vent nipple repair on the back of the tank that I had done earlier to make sure that it was not closed back off again (like it did my first repair). Of course it’s hard to get to…. When I put a tube on the nipple and try to blow into the tank, I can’t get any (or very little) into the tank. Since air is supposed. to vent OUT of the tank back to the canister, you’d think that you could blow INTO the tank. When I blow in the tube, it pressurizes and then comes right back out with gas vapors. So maybe some air is coming out, but not enough to vent while filling the tank.
Using various tools, I know that I’m clear back to where the nipple turns down, and using a dental pick with a hook on the end, I can ddrop the end into the downturn part, but not very far. I don’t think anything from my repair would have resulted in a restriction lower in that elbow.

Does anyone know for sure if you should be able to blow into the tank, or is there maybe a one-way check valve made into the nipple assembly to prevent anything from getting in? Seems like the tank should not be venting to the canister all the time??
 
There is a plastic flapper inside the gas tank. I had to remove whole thing to replace my fuel pump. Was bleeding pressure back into pump, not needed fix but did it before it decided to quit on me away from home.
Just inside main fill tube flapper to prevent cyphoning of fuel I guess, only purpose I can think of made my draining attempts almost impossible from that fill port. I'll post picture of under side port I'm speaking of.
 
I had an 02 Explorer, by design there is a flapper / valve at the inlet to the gas tank. I believe it is to prevent gas from coming out in a rollover. I have no idea why it closed on me, but I had the same symptoms, very difficult to fill teh tank. My solution, with the tank < 1/2 full raise the rear of the truck high.. disconnect the fill line to the gas tank.. reach in with my hand to reset the "valve". Problem resurfaced about 5 years later, but this time I knew what to do.. After 18 years of good service, I gave teh explorer to a relative, and showed what to do if it happened again. Sadly he ruined the truck in a few months...
 
Hey Guys! I'm a long time Avalanche owner (2012, LT, 4x4, flex fuel). I'm having a similar issue where it won't take gas except for a slow trickle. I've read about similar issues on this forum and I've already done all those remedies: replaced the evap canister (charcoal filter), cleaned out all the lines, replace evap solenoid, and smoke tested the tank to find some bad fittings that were also replaced. Now the issue seems to be a check valve that is inside the fuel tank just inside where the fuel filler hose meets the tank. My mechanic is being told that part is unavailable and our best bet is to get an entire replacement tank from the secondary market or salvage yard. Any other options out there? Could this "check valve" actually be the flapper like you're talking about and can I just remove it?
 
Hey Guys! I'm a long time Avalanche owner (2012, LT, 4x4, flex fuel). I'm having a similar issue where it won't take gas except for a slow trickle. I've read about similar issues on this forum and I've already done all those remedies: replaced the evap canister (charcoal filter), cleaned out all the lines, replace evap solenoid, and smoke tested the tank to find some bad fittings that were also replaced. Now the issue seems to be a check valve that is inside the fuel tank just inside where the fuel filler hose meets the tank. My mechanic is being told that part is unavailable and our best bet is to get an entire replacement tank from the secondary market or salvage yard. Any other options out there? Could this "check valve" actually be the flapper like you're talking about and can I just remove it?
I had teh same issue on an 02 Explorer..

What I did..



Jacked up the rear (the fuel fill entered near the rear of the tank) to get all the gas already in there in the front.

Disconnected the fill line.

reached in with my hand to reset / unlock the check valve..

put it all back together.

restored the ability to fill at full flow.
 
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