Gas tank hard to fill

[BowTieOgre]

...and no im not just talking about the gas prices!

Every time I go to fill up the '80 I have to baby the filler trigger down to about 15% otherwise it cuts off like its full. As the tank gets closer to full I can get it up to about 50% but anything beyond that prompts a shut off. This morning I didnt have the nozzle all the way in (1/2" from all the way) and I got gas everywhere. Anyone have any ideas?

[bowtier]

Mine's the same way.
I think it's the filler hose where it curves to connect to the tank. Mine looks slightly kinked at the bend and I think it just restricts the flow. I've found if I keep the nozzel just inside the hole, far enough I'm not spilling gass out (maybe 3/4"), I can fill at almost full bore.

Just a guess. Mine hasn't bothered me enough to mess with.

[moneyeater]

I have the same problem.Would be nice to hear about that!

[68GMC454]

i wonder if it has something to do with what ever keeps you from getting a siphoning hose down it.. my 84 was the same way, you could only put the nozzlle in just a little, ad even then couldnt go to fast when filling it up... i do know that it is either the bend in the line or somethign in it, but you cant get a hose down there to siphon the hose out, i really tried to..lol

[chevymotocross]

My 87 has that problem.... but only at certain gas stations. The one I always go to, I just set the pump on auto fill and let it do its thing. Other stations I go to, I can't hold the trigger more than 1/4 of the way or it will stop pumping.

[xtreme80]

Whaddya know, my 80 is the same way.

Some places it works at, some it doesnt, some pumps it works at, some it doesnt. I'm almost positive it's the design inside the gas tank. If you've ever seen inside the tank, the filler neck makes a sharp curve in there and goes through the tank horizontally. I would be willing to bet that this is the cause of it. I also think that if you somehow vented the tank differently, it might solve the problem.

if it does it again, try twisting the nozzle as if you were filling it from the side rather than straight ahead. This is what I do and it helps.

[old Rusty C10]

hmm vent hoses not right?

[BowTieOgre]

I crawled under it tonight and didnt see any kinked hoses but the metal portion of the fill tube (near the cap) has kind of a flat spot on the bottom where it changes the angle and connects to the rubber hose...maybe im sticking the nozzle in too far and it is bottle necking right there giving a false full cut off. I will try a more shallow approach next time I gas up.

[PhilaTruck]

If you smell gas in the engine compartment and it's not coming from the carb, it could be the charcoal canister. Of course, that didn't help mine. Prolly a vent hose, as mentioned earlier.

[GMC69]

Well I just got my truck on the road last night, and went to fill it up for the first time. I ran into the same problem. Took forever to fill that tank up, and it barely flowed in. I had a feeling I was going to have an issue cause I tried to fill it with a jerry can the other night and it kept coming back at me. I figured then, it was the can causing the problem, but I guess not.


One side note, is that I had put 5 gallons in the truck when I first got it and had another tank on it, which I later discovered had a hole on top and let a bunch of water in it. That tank had no issues when filling with a jerry can.

I did talk to the previous owner, and he also said that you had to find the sweet spot when filling the truck.

I am going to try a different station tomorrow and put a bit more gas in it.

[71swb4x4]

It sounds to me like you have a plugged or restricted vent hose. It's not allowing the air to come back out. Replace the vent hose and all should be good.

[BBEEP]

Had exactly the same problem. It WAS the vent line. Be sure and replace it with fuel hose and resist the temptation of grabbing a leftover heaterhose. It will work for a while and then fall apart from the inside, filling your tank with crap!

[Mickey_D]

Both tanks on my 81 are extremely picky about how I fill them.

I've found that if you rest the nozzle part way in to the filler hole, then only put the auto latch on the first notch, it will fill from empty to about 3/4 - 7/8 full. Then let it sit for a minute (for the bubbles and foam to go down) then click it on to the first notch again, it will fill all the way up.

I've talked to MANY people around here that have the same type of truck and they all have the same problem. It's just something we've all gotten used to dealing with.

[GMC69]

Well my problem is now fixed.

I checked the vent tube and it was clear. But I did notice that the angle at which the filler hose was sitting, didn't look quite right.

I had a spare one from a tank I bought, and decided to swap them out. This one has less of a bend just before it goes into the tank, and it works like a charm. I was able to fill it up at full tilt. I did have to make sure the nozzle wasn't sitting on the flat piece at the bottom of the filler neck, but other than that, it's great.

[chev74]

i think its the newer 'safer' gas pumps. they are more sensitive and were not designed for our trucks.