fuel fill problem

[lowe137]

i have a 76 chevy shortbed fleetside... when i put gas in it the gas pump wont stay on.. i have to hold the handle at its slowest seetting.. it takes me 15 minutes to put 20 bucks in the tank... i noticed when i take off my gas caps that there is alot of suction... this happens on both tanks... any ideas on what to look for.. like maybe some vent lines or something..thanks guys...

[msgross]

sounds like a vent line plugged, check the one that's near the fliier neck and then see if there is another one on the tank... Do you have dual fillers?

[lowe137]

yea my truck has dual fillers... and it happens on both tanks... maybe someone plugged something.. it looks like the switching valve is new.. hopefully ill get a chance to look at my vent lines tonight...

[msgross]

must be a shared vent line that somebody messed with.. I doubt that it's the filler vent line on BOTH tanks...

[lowe137]

ok i found the vent line for both tanks T into one line then connect to a metal line on the frame rail. the metal line is plugged... it runs all the way to the engine compartment near the steering box.. with both ends open i cant blow air through it.. so i just un hooked the line near the tanks and left it open... i put gas in it this morning and no more problems...

[shakedown96]

that is the charcoal can for emissions it would be much safer if you run a new line and hook it up like factory. gasolie vapors are not anything to mess with

[powerdriver 1958]

Not sure about your truck.I have run in to non vented gas caps on truck / cars that should be vented.Have seen two tanks sucked in.one was a dodge 3/4 with a plastic tank.Just a thought.

The old 76 I had was the same way filling until the 3/4 hose the run to the filler was moved .the guy that owned it before had used 3/4 heater hose and it was a little long and sagged down so gas would stay in the vent hose and not allow it to vent.BTW use hose that is made for gas not heater hose.vent hose should be positioned so any gas that gets in to it will drain back to the tank

[lowe137]

first off i do have the vent hose on the filler. it looks to be in good shape. and im pretty sure my gas caps are the right ones..
second the line that runs up the frame rail just ends.. and there is no charcoal canister.. its been gone for a while i guess... besides getting a cansiter is there a another way to hook it up. like a filter, or near the air cleaner, how are these vent lines hooked up on vehicles that dont have canisters...

[Mudder]

Not sure what it is called but you can get a little plastic valve that will let air in but wont let anything out.

[dammitmitchell]

"one way check vaulve"
that's what it's called =-)

[msgross]

Originally Posted by dammitmitchell

"one way check vaulve"
that's what it's called =-)

I need to add one of those to mine..

[lowe137]

just a thought but wouldnt you want it to vent both ways... as fuel level gets lower air needs to enter the tank right?. my gas caps do not breath...