Unexpected Fuel Tank Nipple - Forward Tank - 1973 23'

[SteveW]

Greetings from Southern California !!

After filling with gasoline fuller than I usually do - I noticed some dripping fuel when I got to my storage unit. Drivers side - pretty much right
behind the mid wheel.

I figured that it must be a vent line since the tanks were fuller than normal. And I figured that some driving would consume enough fuel to stop the
dripping. I drove it home and parked outside - slightly tilted to the curb - and no dripping. I guess that I didn't drive enough as it was still
dripping when I returned to storage with a level floor...

Upon inspection - I found an unexpected nipple on the forward tank, drivers side, side of tank, near the top. Attached to this nipple was a short
section (3" of so) of 3/8" (ID) fuel line that was terminated with an inserted bolt and a hose clamp. This short piece of hose was cracked and
deteriorated - and dripping !! So I bled off some gasoline and tilted the coach such that fuel was not at the nipple. And I fashioned a temporary
hose/plug so as to not have gasoline venting into the warehouse.

I had other obligations so I couldn't explore further... Could this nipple be the tank vent for early models ?? Is it supposed to connect to the
separator in the rear wheel well ?? Might it have been intended for the generator fuel pickup (with a pickup tube inside) ?? Anyone else ever
discover this ??

Thank you in advance for any comments and suggestions.

Steve W
1973 23
Southern California

--
Steve W
1973 : 23'
Southern California

 

[jim kanomata1]

Steve,
That is what someone did . Not a factory work.
Possibly a return fuel device. Just replace it with a new fuel line.

On Sun, Oct 27, 2019 at 2:48 PM Steve Weinstock via Gmclist <

> Greetings from Southern California !!
>
> After filling with gasoline fuller than I usually do - I noticed some
> dripping fuel when I got to my storage unit. Drivers side - pretty much
> right
> behind the mid wheel.
>
> I figured that it must be a vent line since the tanks were fuller than
> normal. And I figured that some driving would consume enough fuel to stop
> the
> dripping. I drove it home and parked outside - slightly tilted to the
> curb - and no dripping. I guess that I didn't drive enough as it was still
> dripping when I returned to storage with a level floor...
>
> Upon inspection - I found an unexpected nipple on the forward tank,
> drivers side, side of tank, near the top. Attached to this nipple was a
> short
> section (3" of so) of 3/8" (ID) fuel line that was terminated with an
> inserted bolt and a hose clamp. This short piece of hose was cracked and
> deteriorated - and dripping !! So I bled off some gasoline and tilted the
> coach such that fuel was not at the nipple. And I fashioned a temporary
> hose/plug so as to not have gasoline venting into the warehouse.
>
> I had other obligations so I couldn't explore further... Could this
> nipple be the tank vent for early models ?? Is it supposed to connect to
> the
> separator in the rear wheel well ?? Might it have been intended for the
> generator fuel pickup (with a pickup tube inside) ?? Anyone else ever
> discover this ??
>
> Thank you in advance for any comments and suggestions.
>
> Steve W
> 1973 23
> Southern California
>
>
> --
> Steve W
> 1973 : 23'
> Southern California
>
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>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502

 

[Matt Colie]

> Greetings from Southern California !!
>
> After filling with gasoline fuller than I usually do - I noticed some dripping fuel when I got to my storage unit. Drivers side - pretty much
> right behind the mid wheel.
>
> I figured that it must be a vent line since the tanks were fuller than normal. And I figured that some driving would consume enough fuel to stop
> the dripping. I drove it home and parked outside - slightly tilted to the curb - and no dripping. I guess that I didn't drive enough as it was
> still dripping when I returned to storage with a level floor...
>
> Upon inspection - I found an unexpected nipple on the forward tank, drivers side, side of tank, near the top. Attached to this nipple was a short
> section (3" of so) of 3/8" (ID) fuel line that was terminated with an inserted bolt and a hose clamp. This short piece of hose was cracked and
> deteriorated - and dripping !! So I bled off some gasoline and tilted the coach such that fuel was not at the nipple. And I fashioned a temporary
> hose/plug so as to not have gasoline venting into the warehouse.
>
> I had other obligations so I couldn't explore further... Could this nipple be the tank vent for early models ?? Is it supposed to connect to the
> separator in the rear wheel well ?? Might it have been intended for the generator fuel pickup (with a pickup tube inside) ?? Anyone else ever
> discover this ??
>
> Thank you in advance for any comments and suggestions.
>
> Steve W
> 1973 23
> Southern California

Steve,

That empty stub is on every '73 that I have been under and even a '74. Nobody knows why it is there. It is thought by some to have been planned as a
fuel tap for the generator, but honestly, Nobody knows.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[steve southworth]

It is the return port for the earliest fuel vapor separator. It is OEM including the rubber tube and plug. This separator is shown in the early
manuals. I can't remember right now where i found that info, however it is shown here:

http://www.gmcmhphotos.com/photos/fuel-tank-r-26amp-3b-r/p13484.html

I presume all the early gas tanks have it even after the change to the system we usually see. it can take a while for changes to show up n production
parts.

It would not be a good fuel return as it would splash and aerate the gas.

--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

 

[Matt Colie]

> It is the return port for the earliest fuel vapor separator. It is OEM including the rubber tube and plug. This separator is shown in the early
> manuals. I can't remember right now where i found that info, however it is shown here:
>
> http://www.gmcmhphotos.com/photos/fuel-tank-r-26amp-3b-r/p13484.html
>
> I presume all the early gas tanks have it even after the change to the system we usually see. it can take a while for changes to show up n
> production parts.
>
> It would not be a good fuel return as it would splash and aerate the gas.

Steve,

That is interesting. I had done a search for the purpose of that feature and come up empty.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[SteveW]

Thank You Jim, Matt, and Steve.

I'll plug it and move along to the next project...

SW

--
Steve W
1973 : 23'
Southern California