Gas Tank filling problem

[thomas g. warner]

Isn't that what the rubber frame spacers are supposed to do?

>In a message dated 12/1/98 1:44:48 PM Eastern Standard Time,

>
>> When I replaced the hoses and vent lines last year
>> I made some 4" x 4" x 1/2" exterior plywood blocks and glued them on top of
>> my
>> tank with silicone next to the vent hoses
>Thanks Emery;
>
>I will do something like that too! now , maybe a chunk of rubber.
>Another potential problem solved!
>
>Emery again thanks for the input
>
>Scott Adohen
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

 

[thomas g. warner]

Maybe I am missing something Emory. Wish I had a scanner so I could show
you the pictures of a complete GMC frame on display at Golbys in Orlando
Florida. I took a lot of picutes of in February 98. It clearly shows the
fuel tank inlets and the routing of all hoses from and to the tanks,
including the vents. It does not show any lines going across the frame. Is
their display incorrect?
The frame insulators between the frame and the floor should provide the
proper clearance for the tank inlets and hoses across the tip of the tanks.
Since there were no wooden blocks on top of the tanks for 2o years why do we
need them now?

Is this correct or not?

>No - the frame spacers are between the frame and the body supports. They will
>keep the air hoses from crushing where they go over the frame but the gas
>tanks are between the frame rails. The vent hoses were being pinched between
>the floor and the top of the gas tank.
>
>Emery Stora
>77 Kingsley
>Santa Fe, NM
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach

 

[heinz wittenbecher]

I'll jump in with my cents

The vent and possibly the fuel line gets squished on top of the tank as
over the years the insulation used in the floor (under the floor) expands
and exerts pressure on the inlet on top of the fuel tank. The problem can
manifest itself by fuel overflowing as you "fill" the tank to the top
because a fitting broke/cracked to improper venting as the ventline is
squished.

The vent line does come out between top of frame and coach frame at the
left wheel where the infamous air/fuel seperator resides.

A lot of venting at fillup time occurs through the ventline to the
seperator. I know, because I use that as a gauge to stop filling as fuel
starts to spit out. (Modified vent scheme as my seperator no longer seperates)

I've had to do both tanks over the years and last time we inserted a 1 1/2
x 1 1/2 piece of wood to give the tank more room on the top. (we extended
the bolts that hold the tank straps).

Next time the tanks are down I'll rework the under floor, but in the
meantime it works.

Heinz
'76 Transmode

>Maybe I am missing something Emory. Wish I had a scanner so I could show
>you the pictures of a complete GMC frame on display at Golbys in Orlando
>Florida. I took a lot of picutes of in February 98. It clearly shows the
>fuel tank inlets and the routing of all hoses from and to the tanks,
>including the vents. It does not show any lines going across the frame. Is
>their display incorrect?
>The frame insulators between the frame and the floor should provide the
>proper clearance for the tank inlets and hoses across the tip of the tanks.
>Since there were no wooden blocks on top of the tanks for 2o years why do we
>need them now?
>
>Is this correct or not?
>
>

>>No - the frame spacers are between the frame and the body supports. They
will
>>keep the air hoses from crushing where they go over the frame but the gas
>>tanks are between the frame rails. The vent hoses were being pinched between
>>the floor and the top of the gas tank.
>>
>>Emery Stora
>>77 Kingsley
>>Santa Fe, NM
>>
>>
>Tom & Marg Warner
>Vernon Center NY
>1976 palmbeach

 

[bartz paul]

I know of an individual who used steel brake line over the top of the tanks
in an attempt to overcome/avoid the hose pinching problem.

Paul Bartz

From: EMERYSTORA [mailto:EMERYSTORA]
Sent: Wednesday, December 02, 1998 11:03 AM
Subject: Re: GMC: Gas Tank filling problem

You are correct. There are no fuel lines or vent lines going over the top
of the frame rails. There are vent lines and fuel outlet lines lying on top
of the gas tanks. There are indentations in the top of the tank where the
lines should run but they don't give much clearence and the lines still get
squished somewhat. I am told that GM used some fiber blocks to space the
fuel tanks from the floor and there were a couple of them still in place
when I dropped the tanks. I added more blocks because the lines had been
flattened in places. You could also use pieces cut out of a rubber tire as
spacers. The lines run to the driver's side frame and go along the inside
channel to the front of the motorhome.

 

[hdavis]

>
>In a message dated 12/2/98 12:04:04 PM Eastern Standard Time,

>
>> I know of an individual who used steel brake line over the top of the tanks
>> in an attempt to overcome/avoid the hose pinching problem.
>>
>Hi Paul
>
>Good idea, I only have copper line left, anyone see a problem if I used
>copper, rather than steel? Just thinking, that hurts, doing this might make
>the removal and replacement difficult in the future. I think I have a great
>advantage over most of you since I can work without the coach in the way.
>

Copper will work harden as it flexes. Flex it too much and it breaks. YOu may also need to be concerned about the potential
added flow restriction.

Henry

Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (408) 462-5199 / full service marketing
fax: (408) 462-5198
http://www.henry-davis.com

 

[zachary zehnacker]

Scott,

I don't know if I like the idea of using hard line to connect these items.
Crushing problems would be just as likely as they would with rubber, and
abrasion problems would probably be worse. I believe previous comments
about the down sides of using copper for the airlines would also hold true
for the gas lines. I would suggest buying the expensive fuel-injection
hose and using that if you are really worried about it. The tanks have
some bumps in them that space them away from the floor of the motorhome.
The sending unit actually takes up more height than any of the hoses when
they are run in the correct channels. We used tape to hold the lines in
the channels for installation. If the sending unit clears, then there
should be no problems with the hoses. If the sending unit doesn't clear,
then you have more problems than just crushing your hoses.

Zak


>Good idea, I only have copper line left, anyone see a problem if I used
>copper, rather than steel? Just thinking, that hurts, doing this might make
>the removal and replacement difficult in the future. I think I have a great
>advantage over most of you since I can work without the coach in the way.
>
>Scott Adohen