Fuel filler issue. This can’t be right.

[soliddrummer]

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New to me 1980 k3500 with saddle tanks. First time at the gas station after purchase and could NOT get gas in this truck. Put $20 in and $12 worth on the ground. Tried every which direction on the nozzle and just couldn’t get gas in this truck. Looked up underneath and both sides are like this. The filler hose runs UPHILL. So the gas just pools in the flat area and drizzles very slowly over the hump and into the tank. It took me 30 minutes to get a few gallons in. This cannot be right.

 

[soliddrummer]

I also realize there may ALSO be vent issues, but this angle of the filler tube can’t ever have worked. How was the previous owner driving this truck for 30 years?

 

[AuroraGirl]

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Heres my stock passenger side tank (non functional, rusted badly on the filler neck, and a few holes in the tank)
seems like your filler is probably correct. I have a truck that had the ability to use leaded gas, since it was a LT9 (HD emissions), I assume you are the same? Wide mouth filler neck with no reduced opening for unleaded fuel nozzle? Vented gas cap? The vent hose in your setup may have a restriction, remove it and look in it and reinstall it.

 

[AuroraGirl]

It looks like your filler hoses may be a little in a bind , reducing their diameters. I would loosen the clamps at the filler and get them unbound

 

[jagbuxx]

I have the same issue filling my 77 C10. The huge evap deals they put on the nozzles now certainly aren’t helping.

 

[Grit dog]

Looks just like my 77. Nothing wrong it’s how it is. Have to have the gas nozzle at just the right angle.
And yeah the stupid new gas nozzles don’t help.
Haven’t tried a race jug but it might be easier.
Open to hearing anyone’s tricks to make it easier.
It’s not the vent. Vent don’t matter when filling as it’s not sending a solid stream of fuel down. There’s room for air

 

[soliddrummer]

My truck is a 1980 so the leaded gas option is a no. It’s a very stock truck, and the fill tubes are not bound up in any way. I MAY have a venting issue that I will look into further, but I am baffled how this filler setup has ever worked. The only way I could see it working at all is if the gas nozzle was an extra 4-6” in length so it could reach further inside the filler and avoid the flat section altogether. I cannot wrap my head around how this has been functional for 40 years.

 

[AuroraGirl]

My truck is a 1980 so the leaded gas option is a no. It’s a very stock truck, and the fill tubes are not bound up in any way. I MAY have a venting issue that I will look into further, but I am baffled how this filler setup has ever worked. The only way I could see it working at all is if the gas nozzle was an extra 4-6” in length so it could reach further inside the filler and avoid the flat section altogether. I cannot wrap my head around how this has been functional for 40 years.

I Dont think you read me.

I have a 1980 GMC. I have leaded gas engine as OEM equipment. My gas gauge says nothing about unleaded fuel. The only way to get the HD emissions(leaded fuel) was to be above 8600gvw in 1980. you say you have a k30 right? I have a k25, c6p/f44.

 

[AuroraGirl]

What is your Engine RPO code on your Service Parts Identification Label in your glovebox? the blue sticker

 

[soliddrummer]

I Dont think you read me.

I have a 1980 GMC. I have leaded gas engine as OEM equipment. My gas gauge says nothing about unleaded fuel. The only way to get the HD emissions(leaded fuel) was to be above 8600gvw in 1980. you say you have a k30 right? I have a k25, c6p/f44.

Wow. Ok. This is news to me. It’s a k35 1 ton dually. I’ll have to check the glove box sticker when I’m there next (it’s at my shop). I had no idea we were still doing the leaded fuel dance in the 1980 model year. It does indeed have a wide mouth filler with no small hole as in modern fillers. And so am I correct to assume the leaded gas nozzles were setup in such a way that they stuck down further into the filler tube?

 

[soliddrummer]

What is your Engine RPO code on your Service Parts Identification Label in your glovebox? the blue sticker

My truck is LT9. I found it on the build sheet.

 

[AuroraGirl]

My truck is LT9. I found it on the build sheet.

so you have a larger than most filler neck, that has no built in reducer to limit the nozzle size like most filler necks do, and you have a vented gas cap, and you have an engine that should use lead substitute assuming its not rebuilt , you never had cat converters either.

 

[AuroraGirl]

Wow. Ok. This is news to me. It’s a k35 1 ton dually. I’ll have to check the glove box sticker when I’m there next (it’s at my shop). I had no idea we were still doing the leaded fuel dance in the 1980 model year. It does indeed have a wide mouth filler with no small hole as in modern fillers. And so am I correct to assume the leaded gas nozzles were setup in such a way that they stuck down further into the filler tube?

I am not sure if they stuck further, but unleaded vehicles used a smaller nozzle at least to make it so you couldnt fill up so easily with leaded gas in an unleaded car. I assume old leaded nozzles were probably the same size as a diesel nozzle but i have no proof of that

 

[DoubleDingo]

The old nozzles were bigger. New nozzles are smaller. My 81 has the big holes and I can fuel up each side at any flow rate and not a drop comes out onto the ground. Can wash windows, check fluids, no babysitting the nozzle.

 

[soliddrummer]

The old nozzles were bigger. New nozzles are smaller. My 81 has the big holes and I can fuel up each side at any flow rate and not a drop comes out onto the ground. Can wash windows, check fluids, no babysitting the nozzle.

This is my train of thought as well. Since the filler tube is bigger, it should flow gas at any rate, but due to the angle of the filler tube, the gas builds up in the flat, and splashes back. I tried every angle and flow rate and gas just wouldn’t go in. I’m no dummy, I’ve had old cars/trucks my whole life and I’ve never experienced this. I cannot understand or figure out how this filler was designed to actually work.