Fuel Filler question 1966 C10

[66C10LB]

I have built my idea of a fuel filler setup for my 66 C10. I am not very experienced with fuel systems so I was wondering if others know if it is important to add a fuel overfill/vent connected into the filler neck close to the filler cap, OR if it is enough to run a fuel vent line that is not connected to the filler neck using hose and a rollover valve. (Fuel filler is positioned on the INNER wall of the Fleetside bedside) Any ideas would be appreciated. Pictures for reference....

[caseyjones]

I just installed my fuel filler in a similar spot on my GMC. I don’t have a vented cap so I installed the rollover vent about 3-4 inches above the fuel cap. I still get a little bit of fuel pushing out of the vent after I fill up and the truck sits-I assume the fuel is expanding with heat and pushing up the vent line. If you have a vented cap, I suggest you route the vent line to the filler neck to avoid my situation.

[bigmoe]

I have my vent/rollover valve mounted up high between the inner and outer fender and a non-vented boat filler cap to fill. My routing is similar to yours and I have to fill slowly or it gurgles back on me. Nothing burping out the vent.

[66C10LB]

Originally Posted by caseyjones

I just installed my fuel filler in a similar spot on my GMC. I don’t have a vented cap so I installed the rollover vent about 3-4 inches above the fuel cap. I still get a little bit of fuel pushing out of the vent after I fill up and the truck sits-I assume the fuel is expanding with heat and pushing up the vent line. If you have a vented cap, I suggest you route the vent line to the filler neck to avoid my situation.

Great to see that you got the filler up and off the bedwood. My filler cap is the push through non vented type because the flush fuel door is very small. I will be using this hardware (in the picture) to create a 5/8 overflow/vent near the cap, then into the supplied inlet into the Boyds tank. There is also a separate 1/4 inch rollover vent built into the tank.

[66C10LB]

Originally Posted by bigmoe

I have my vent/rollover valve mounted up high between the inner and outer fender and a non-vented boat filler cap to fill. My routing is similar to yours and I have to fill slowly or it gurgles back on me. Nothing burping out the vent.

Great spot for easy access! Slower fill is not so bad if you can sit on the tailgate.

[Justin71105]

Filled mine today at the gas station, it overflows quickly with the inline filter No Limit sent with the tank. So had to fill super slow.

But when I took that filter off it vented ok, 1/4" hose for vent tube.

Going to move up to 5/16 line when I do my bed fuel door and get the same filter you show.

That line size should take care of venting pretty good for you.

I am going to run the vent line up in the stake pocket hole.

Should be high enough and hopefully be able to fill with full handle pull.

[66C10LB]

Originally Posted by Justin71105

Filled mine today at the gas station, it overflows quickly with the inline filter No Limit sent with the tank. So had to fill super slow.

But when I took that filter off it vented ok, 1/4" hose for vent tube.

Going to move up to 5/16 line when I do my bed fuel door and get the same filter you show.

That line size should take care of venting pretty good for you.

I am going to run the vent line up in the stake pocket hole.

Should be high enough and hopefully be able to fill with full handle pull.

This is a rough mock up of what I have done except I have made a bracket (to be welded soon) to hold the filter separately. So, 5/8 return line connected to a bung that is welded high on the filler neck. 5/16 line from the rollerover vent to the small air filter.

[Justin71105]

Looks good, received my fuel box this week and will be starting it next weekend.

Went with the curved version, hopefully its close to the bedside curve when mounted.

But mainly fills easily with less overflow and is easier to insert nozzle vs my behind brake light setup.

[Justin71105]

Got mine finished today, does not look the best but it works for sure.

You should have no issue with the larger vent line.

I have the 1/4" still and eas able to lock the nozzle with fastest fill and it never overflowed.

Well when it was full it did but the nozzle clicked off on its own. Only lost a few tbs on ground.

7 gallons in maybe a minute or so, very happy with it.

[vet57air]

Originally Posted by 66C10LB

I have built my idea of a fuel filler setup for my 66 C10. I am not very experienced with fuel systems so I was wondering if others know if it is important to add a fuel overfill/vent connected into the filler neck close to the filler cap, OR if it is enough to run a fuel vent line that is not connected to the filler neck using hose and a rollover valve. (Fuel filler is positioned on the INNER wall of the Fleetside bedside) Any ideas would be appreciated. Pictures for reference....

I have the same cap as you and have no overfill vent. I started with a 3/8" vent in the tank and it was a chore to fill. On my intank fuel pump It had a provision for a 1/2" vent, I used this and now I have no worries filling.

[AcampoDave]

Originally Posted by Justin71105

Filled mine today at the gas station, it overflows quickly with the inline filter No Limit sent with the tank. So had to fill super slow.

But when I took that filter off it vented ok, 1/4" hose for vent tube.

Going to move up to 5/16 line when I do my bed fuel door and get the same filter you show.

That line size should take care of venting pretty good for you.

I am going to run the vent line up in the stake pocket hole.

Should be high enough and hopefully be able to fill with full handle pull.

I ran mine up the stake pocket too. Works great and funny when guys gather around the bed in the summer and someone on that corner says "I smell gas."

[Justin71105]

If you break the cheap magnetic latch in the box like I did you can get them from amazon very cheap. Can get a 2 pk for $5, swapped mine out today.

Also home depot carrys them, but only found it in brown there.

[66C10LB]

Originally Posted by Justin71105

If you break the cheap magnetic latch in the box like I did you can get them from amazon very cheap. Can get a 2 pk for $5, swapped mine out today.

Also home depot carrys them, but only found it in brown there.

Good to know. Thanks

[66C10LB]

So, here's the filler and venting layout. Vent line from the tank's rollover vent (with air filter on it), Overfill/venting line near filler neck, and of course the filler neck. All squeezed between the inner and outer bedside walls (the filler door is on the inner bedside wall).