78 c20 gas filling issue!

[55dude]

When I fill it it wants to run down the side of box like their is blockage,is their a vent that could be blocked? I even fill it slow and it still does it. Thanks
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[Ziegelsteinfaust]

I have the same problem, and it due to the new style of pumps they use. You could still check your vent as it could be a problem, but california is famous for this issue.

On my truck I have to rotate the pump handle 90*, and aim the fuel down the pipe. Otherwise I would never be able to fill up.

[55dude]

Thanks,anyone else?
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[55dude]

Bump!
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[donut]

Ok, very common problem with no real "fix" (that I know of). Your vent is located in the filler neck, hose runs parallel to fill hose.
Hold nozzle sideways, upside down, pull it back a smidge when filling, fill slower. find something that works for you.

If you pull a sight search, it should keep you reading for the afternoon.

[75chev4x4]

I just hold the handle myself and fill it up slow, just the way these old trucks are.

[Sabaka454]

Single or dual tank? Where does your tank vent go?

[tucsonjwt]

I agree with the problem being the new design of the gas pump nozzles. The new nozzles have a wire wrapped around the nozzle, are shorter, and have a sharp curve - relative to the older style that has no wire and a longer, gentler curved nozzle.

Here is my theory - when you pump gas the gas shoots against the side of the filler neck, causing the gas to feed back into the nozzle trigger, which causes the nozzle to sense an overflow condition and shut off.

If you try turning the nozzle sideways or completely vertical, this might cause the gas to flow without shutoff. However, this seems to cause the nozzle to get stuck in my truck (both tanks), so it really does not work for me. So, I just hold the trigger slightly depressed and slowly fill up the tank (I have dual tanks, so it takes a while.) Fortunately, I only drive truck about once a week on average, so I don't have to fill up very often.

If you can find a gas station that still has the old style long, smooth nozzle you could try it to see if the theory is correct. We still have one or two stations like that around here, but the gas is more expensive there so I don't use them.

[oily]

Had the same problem especially at one pump.
I removed the filler pipe from the truck and checked for an obstruction inside the filler and vent--nothing. Then I used a tapered reamer and increased the two little holes in the inlet [3/16"] to as big as I could ream them [5/16"].
Problem solved.