Author Topic: 73 C10 fuel filling problem solved  (Read 10643 times)

Offline markolson

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73 C10 fuel filling problem solved
« on: January 11, 2015, 10:15:11 PM »
My son's 73 C10 fleetside has been a PITA to fill with fuel using modern fuel pump nozzles here in California.  The fuel keeps backing up and spilling on the ground, unless the fuel is just dribbled in slowly.  It was always taking forever to fill the tank and there was always spillage.

I finally decided to do something about it, so I bought a donor filler neck from a junkyard 74 and used it to fabricate a new filler neck that allows him to fill his tank as fast as the pump can pump.  FYI, it requires the fuel filler hose from a 79 truck.

Here is the writeup I did for the project: https://img1.wsimg.com/blobby/go/1975f84f-4935-4131-8404-5a914da1afb7/downloads/1c2d31vtv_228632.pdf  (It was too big to attach.)  (File location updated 10/27/2018)

Hope you enjoy it.

« Last Edit: October 27, 2018, 11:34:39 PM by markolson »
73 Chevy C10 Fleetside Short Bed (my son's truck).  350/TH350

Offline Captkaos

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Re: 73 C10 fuel filling problem solved
« Reply #1 on: January 13, 2015, 10:04:20 PM »
Did you check the hose you removed to see if it was stopped up?  I have never had much of an issue filling one up fast in stock form.

Offline markolson

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Re: 73 C10 fuel filling problem solved
« Reply #2 on: January 13, 2015, 11:40:30 PM »
The hose we removed was clear and only a few months old.  That was definitely not the problem.

It just refused to accept fuel...
73 Chevy C10 Fleetside Short Bed (my son's truck).  350/TH350

Offline Jason S

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Re: 73 C10 fuel filling problem solved
« Reply #3 on: January 14, 2015, 09:50:54 AM »
Markolson, that's looks like a neat fix for your fueling problem.

When I had the original bed (with flush fillers) on my '73, I seem to remember issues with pumps in the Dallas/Fort Worth area that had the vapor recovery nozzle (i.e. 'funky rubber nozzles' as an old TV advertisement called them).  Pumps outside of DFW area, without the vapor recovery, worked just fine.

I recall something about having to keep the vapor recovery shielding pulled back or slowly filling when fueling at those kind of pumps...
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Offline markolson

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Re: 73 C10 fuel filling problem solved
« Reply #4 on: January 14, 2015, 11:01:40 AM »
We did need to keep the vapor recovery shielding pulled back and still had lots of trouble getting the fuel in.

But I think you are right.  I think pumps without the vapor recovery system are not a problem.  Of course here in the Bay Area, they all have the vapor recovery systems...
73 Chevy C10 Fleetside Short Bed (my son's truck).  350/TH350

Offline Dr_Snooz

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Re: 73 C10 fuel filling problem solved
« Reply #5 on: January 14, 2015, 09:08:02 PM »
Cool project. FWIW, my '86 is also a bear to fill with the new pumps. As I recall (from when I was like 8 years old), Dad's '79 was also difficult to fill once the new pumps got installed. We had the best results turning the pump handle upside down. In addition to the narrow filler neck, I believe the sharp 90 deg. bend in the filler hose is also part of the problem. That causes a lot of turbulence in the neck with fuel splashing up into the suction on the fuel pump nozzle. The nozzle is designed to turn off when fuel hits the suction port.

On your project, I notice that the filler hose has a slightly less sharp 90 deg. bend in it now. I suspect that helps a lot.
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Offline markolson

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Re: 73 C10 fuel filling problem solved
« Reply #6 on: January 14, 2015, 10:44:33 PM »
It could be less sharp of a bend, but it doesn't look like it's much different to me.  It is also a bigger hose.  Regardless, it is now super easy to fill the tank.  He's really happy with it.
73 Chevy C10 Fleetside Short Bed (my son's truck).  350/TH350

Offline JohnnieB

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Re: 73 C10 fuel filling problem solved
« Reply #7 on: August 05, 2017, 10:21:49 AM »
Mark Olson's modification works like a champ! 

No more spilled gas and it was a fairly simple fix.
The larger filler neck, now 2", and relocating the vent line further up, solved the problem.
Now that fueling up is so fast I feel like I'm in a NASCAR pit stop!

Thanks Mark!

Offline VileZambonie

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Re: 73 C10 fuel filling problem solved
« Reply #8 on: August 05, 2017, 10:57:33 AM »
One of the most common reasons this occurs is the tank vent being capped off, canister removed, bolt stuffed in the hose etc. Check that first before you do this.
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Offline blazer74

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Re: 73 C10 fuel filling problem solved
« Reply #9 on: August 05, 2017, 11:37:24 AM »
On a side note, I had a chevy cobalt that one day would not take gas except super slow.

Blew out the vent no help, pulled the hose off of the tank and out drops a night light bulb. Just the perfect size to block the reverse valve at the inlet to the tank.
Someone's idea of funny.