High Pressure Gas shooting out filler hole

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ocsolarguy

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Brian
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1978
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K20
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400
Hello, I have a 1978 K20 with Dual Gas Tanks with pressure building up in the gas tank as the Truck warms up (10 - 15 minute drive).
I Can see gas leaking out of cap on both sides, when the gas cap is taken off Gas Explodes out the filler hole drenching anything within 3 feet.
I have Installed 2 new tanks, 2 new sending units & 1 new fuel pump since this issue started. Please help.
 

TotalyHucked

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Yep, need to know what you did for a vent. Your truck originally had vent lines going up front to a charcoal canister, something in that system could be clogged. I got rid of all that junk when I LS swapped my truck, I now just have a piece of fuel hose going from the vent along the frame and ends just ahead of the rear bumper. You could try this to see if it alleviates your problem. You shouldn't have vented caps on these
 

MrHorsepowerLSx

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Hellova first post :) Try running the truck with the gas caps off and see if that fixes the issue. If yes proceed to correcting the tank vent issue or replace the fuel cap with caps that are vented
 

Randy and Easton

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agree with all above, needs a vent. We had a similar issue with a strong gas smell around the truck all the time. Had a vented cap at the time (PO). We finally found the vent tube was cut and plugged (PO) by the radiator support and lower radiator hose. Could not find a factory charcole filter at the time so we made one with a fuel filter housing and a fuel tank vent. Cap is non vented now. Has been perfect ever since.

Randy and E
 

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CountKrunk

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You can buy activated charcoal real cheap online. And like above, rig up a canister easily.

Next time, post here before unloading the parts cannon at it.

Welcome!
 

TotalyHucked

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agree with all above, needs a vent. We had a similar issue with a strong gas smell around the truck all the time. Had a vented cap at the time (PO). We finally found the vent tube was cut and plugged (PO) by the radiator support and lower radiator hose. Could not find a factory charcole filter at the time so we made one with a fuel filter housing and a fuel tank vent. Cap is non vented now. Has been perfect ever since.

Randy and E
That's pretty slick! I just have a hose on mine, no rollover valve or filter or anything, but I'd like to add something like that for when it's stored in a small space.
 

ocsolarguy

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I appreciate the advice from everyone.
The vent hoses are connected, not clogged or cracked.
I did take off both gas caps and it took a little longer to spew.
Soo many hoses and make shift vent canisters to know where to start, but I'll take photos.
I will replace all 4 canisters and see what happens

Its the old truck my dad and I used for hunting when I was a kid. I'd like to keep it.
When Dad passed away I found the truck fully submerged in his lake. Drained all fluids and
drove it from Texas to Ca. 3 years ago and this issue just started

There's some real knuckleheads that think their mechanics, I took it to a few of them.
 

SquareRoot

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I appreciate the advice from everyone.
The vent hoses are connected, not clogged or cracked.
I did take off both gas caps and it took a little longer to spew.
Soo many hoses and make shift vent canisters to know where to start, but I'll take photos.
I will replace all 4 canisters and see what happens

Its the old truck my dad and I used for hunting when I was a kid. I'd like to keep it.
When Dad passed away I found the truck fully submerged in his lake. Drained all fluids and
drove it from Texas to Ca. 3 years ago and this issue just started

There's some real knuckleheads that think their mechanics, I took it to a few of them.
4 cannisters? :popcorn:
 

ocsolarguy

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Hellova first post :) Try running the truck with the gas caps off and see if that fixes the issue. If yes proceed to correcting the tank vent issue or replace the fuel cap with caps that are vented
Yeah, I appreciate the help, but I replaced the gas caps - That didn't work, I replaced 2 of the 4 Charcoal Canisters I'm not sure what the other 2 Cans do. Nevertheless, its fixed! I also replace all hoses & rearranged the hoses at that hub thing under the gas tank and somehow it works. I think the last guy I had work on it was drunk !
 

SquareRoot

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Yeah, I appreciate the help, but I replaced the gas caps - That didn't work, I replaced 2 of the 4 Charcoal Canisters I'm not sure what the other 2 Cans do. Nevertheless, its fixed! I also replace all hoses & rearranged the hoses at that hub thing under the gas tank and somehow it works. I think the last guy I had work on it was drunk !
Nothing wrong with being drunk if you know what you're doing. It's better than fixing something and not knowing how you did it.
 

Doppleganger

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Yeah, I appreciate the help, but I replaced the gas caps - That didn't work, I replaced 2 of the 4 Charcoal Canisters I'm not sure what the other 2 Cans do. Nevertheless, its fixed! I also replace all hoses & rearranged the hoses at that hub thing under the gas tank and somehow it works. I think the last guy I had work on it was drunk !
FOUR charcoal canisters? Never saw more than one on anything.

Can you blow air through the vent hose to make sure it doesn't have a blockage upstream like a spiders nest, etc?
 

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