Recent Topics
Olm went off already.
by ram_man
05/27/17 02:03 AM
Rotella T5, 10W-30, old version...
by mattwithcats
05/27/17 12:15 AM
Combating dropping TBN's with vintage MotorGuard
by A310
05/26/17 11:58 PM
Bobcat 6667352 Fuel Filter -Cut Open Kubota Diesel
by bmwpowere36m3
05/26/17 11:43 PM
Bobcat 6675517 -Cut Open- Kubota Diesel
by bmwpowere36m3
05/26/17 11:31 PM
Napa Gold 1085 -Cut Open- Kubota Diesel
by bmwpowere36m3
05/26/17 11:20 PM
2017 Honda Civic 1.5T, factory fill, 2977miles
by researcher
05/26/17 10:05 PM
Gutter Guards?
by Gebo
05/26/17 08:59 PM
75w90 recommendations for GM AWD
by HOG
05/26/17 07:09 PM
Lifespan of Maxima Castor 927 once mixed.
by Surestick
05/26/17 07:04 PM
mPerks $10.00 of $50.00 auto dept
by fdcg27
05/26/17 06:22 PM
VW Diesel Band
by redbone3
05/26/17 04:52 PM
2006 PT Cruiser Under-cover Pics - Seal R&R
by DoubleWasp
05/26/17 03:40 PM
Dealer put in wrong oil?
by fafafooey
05/26/17 02:43 PM
07' CTS V6 ATF & Power Steering
by TX_1821
05/26/17 01:49 PM
Strange Telephone Behavior
by oilpsi2high
05/26/17 01:42 PM
How important is heat cycling when breaking in an
by 5AcresAndAFool
05/26/17 12:46 PM
Fumoto 10% off $100 or $10 off over $100
by knnaz392
05/26/17 12:39 PM
PCV screwed into crankcase rather than valve cover
by friendly_jacek
05/26/17 12:19 PM
Fram Tough Guard 3614 Cut Open- internal damage
by 5AcresAndAFool
05/26/17 12:16 PM
Newest Members
Harleyman08, DannyWatts, TX_1821, TwoDogs, AoS810
61670 Registered Users
Who's Online
19 registered (4WD, d00df00d, bbhero, Bandito440, Char Baby, 3 invisible), 1045 Guests and 9 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
61670 Members
66 Forums
265650 Topics
4390303 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Page 2 of 2 < 1 2
Topic Options
#3311682 - 03/14/14 11:17 AM Re: Gas coming out of tank while filling [Re: Tom NJ]
hsd Offline


Registered: 09/05/09
Posts: 249
Loc: NE
The charcoal canister can not cause overflow during filling as it only functions when the system is sealed up (gas cap is installed).

Top
#3311978 - 03/14/14 04:14 PM Re: Gas coming out of tank while filling [Re: Tom NJ]
1 FMF Offline


Registered: 08/12/02
Posts: 1680
Loc: CT
when i had the back of my 2006 gmc sierra apart, i found that there's a valve in the filler neck of the fuel tank that's spring loaded and stays shut unless a force acts from outside to push it inward, such as fuel when filling. the purpose of it is to prevent fuel from coming out in case of a rollover. i believe all gas tanks have this, and also makes it nearly impossible to siphon gas out of the tank because it will block any hose from making it through. my guess is that valve is sticking or not opening all the way preventing any significant volume of fuel from entering the tank quickly. otherwise everything else is sealed, the evap canister and purge valves are always closed unless commanded open by the pcm. your vent for when filling the tank is a separate small hose that runs alongside the big fill hose and goes to the filler neck thing up on the body where your gas cap is. if you look where you insert the gas pump into that fill neck, there will be a separate small hole there, that's the vent which works when filling the tank because the gas cap is off. but when the gas cap is on then the fuel system is completely sealed.


Edited by 1 FMF (03/14/14 04:16 PM)

Top
#3311989 - 03/14/14 04:22 PM Re: Gas coming out of tank while filling [Re: Tom NJ]
1 FMF Offline


Registered: 08/12/02
Posts: 1680
Loc: CT
also gas with ethanol is quite a solvent, also attracts water, and over time can dry out that plastic valve and make it stick or corrode/rust the metal spring. using some kind of oil, like marvel mystery oil, which you can run with little problem in the fuel, shoot that down the fill neck every now and then to coat that anti-siphon valve and it may get better. otherwise if it's integrated into the plastic tank then you're looking at a new fuel tank.
but don't dump a pint of mmo down the fill neck just before filling up with gas and wash all the mmo down, that'll defeat the purpose.

Top
Page 2 of 2 < 1 2