Dropping fuel tank to repair leak.

[Matt Colie]

Bill,

I did do the "all metal" on top of the tanks. A good way (courtesy of Emery Stora) is to carefully cut the bubble off the steel line on the fuel draw
and vent lines and then use a compression fitting to couple to the new metal (in my case Polyarmor) lines. I used a jeweler's saw for this and then
deburred and blew the lines clear. I had the tanks down five times fighting fuel leaks. This was the last effort about 10 years ago.

I have not yet added electric fuel pumps.

Another good move if you are going that far -
That other line in the center is the fill vent. The two from the both tanks join over the fill line T. Add more line to both and move that T to just
under the cab floor. This will make filling go much better.

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]

Bill -

I discovered a similar issue once after a fuller-than-usual fill up. I arrived at my storage and parked - only to discover dripping gasoling from the
drivers side front end of the front tank...

To my surprise - I found an unexpected unthreaded stub at the topmost corner of the gas tank. It had a small section (2" or 3"") of hose clamped onto
it with a plug (bolt) clamped into its end. Said hose was all deteriorated and leaking.

I removed the deteriorated hose and plugged the hole with a nice vacuum cap and haven't seen a drop since.

Oh... and my mileage improved up to 16 MPG !!

Steve W
1973 23' Yellow
Southern California


--
Steve W
1973 : 23'
Southern California

 

[LarryW]

> Filled the coach last week and found fuel leaking at the front driver's side corner of Aux tank, from above the fill connection. Slow(ish) leak
> and eventually stopped after driving 5 mi and raising rear of coach. I'm home now, and planning to drop the tanks and figure out what's going on -
> once I find somewhere to pump the (50?) gallons of fuel.
>
> In any event, I plan on replacing the rubber supply and vent lines with metal and moving the Onan supply from the Coachman tee to the GM stock
> location. Also splitting off the Aux tank vent and running it forward closer to the fill vent line.
>
> So, one question is how to couple the new metal lines to the sender assembly. I have seen photos of 3/8" compression fittings and others showing
> short rubber nipples with hose clamps. I am leaning towards the rubber nipples - seems like good vibration isolation - and wondering if it's worth
> it to swage a bead on the ends of the new lines.
>
> Another thing I am wondering is whether in-tank pumps are a good idea. Any issues with fuel pump cooling at low fuel levels? Also wondering
> whether leaving the two existing external EFI pumps as a backup makes sense - would they pull through the in-tank pumps?

Maybe this photo set can help you.
http://www.gmcmhphotos.com/photos/g7204-dropping-the-fuel-tanks.html
JWID
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Carl Stouffer]

IF you use rubber hose pieces to couple to your new metal lines, You should probably put a bubble on the new line. If you do NOT install in tank fuel
pumps, it is probably not necessary to 'bubble' flare the lines because there will not be any pressure involved, but it is probably good practice
anyway.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[Carl Stouffer]

Yes, that's how I did it. Just a partial double flare.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member

 

[jim kanomata1]

On Tue, Feb 18, 2020 at 6:38 PM Carl Stouffer via Gmclist <

> Yes, that's how I did it. Just a partial double flare.
> --
> Carl Stouffer
> '75 ex Palm Beach
> Tucson, AZ.
> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
> Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
> Eagles,
> Solar battery charging. GMCSJ and GMCMI member
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

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

 

[jim kanomata1]

For people that want to not go to the metal way, the new rubber hosed
should last 25 years.
if your young and plan on using the coach for 25-35 years, go for the metal
.

>
>
> On Tue, Feb 18, 2020 at 6:38 PM Carl Stouffer via Gmclist <

>
>> Yes, that's how I did it. Just a partial double flare.
>> --
>> Carl Stouffer
>> '75 ex Palm Beach
>> Tucson, AZ.
>> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
>> Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
>> Eagles,
>> Solar battery charging. GMCSJ and GMCMI member
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk
> http://www.gmcrvparts.com
> 1-800-752-7502
>

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

 

[LQQKatJon]

I would believe that leak you are seeing is the vent hose connection. That nipple off the tank, and the hose routing puts a little strain, and
that is usually the first thing to fail. I have seen this on new fuel line installs, where all it took was a little tighting of the hose clamp. It
is very important to use high quality hose clamps that you can get some good torque on, or once the hose shrinks a little, you will have that leak.

otherwise that hose tends to be the first one to crack right where the end of the nipple is on the other side of the hose clamp.

I am running the two tank pumps externally. I think there is enough pro's and con's to either intank, or exterior fuel pumps, it is all just what
you feel comfortable with. I am also fine with rubber lines, as the trade off with going with metal, is adding some joints. Dropping fuel tanks,
really is not a hard project. most of the work, is spent draining, and getting the coach up on the ramps/jack stands.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[johnny]

In tank pumps and outside pumps? 4 pumps? To me that's kind of overkill. Anyway, if you do intank pumps, would it not make sense to also cut access
holes in the floor to allow removal of the pump/gauge/vent assembly without dropping the tanks?
I opted for outside pumps on the 23' and the 26' has the single pump ahead of the selector. Both worked/work OK.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell

 

[Matt Colie]

> For people that want to not go to the metal way, the new rubber hosed
> should last 25 years.
> if your young and plan on using the coach for 25-35 years, go for the metal.
> --
> Jim Kanomata
> Applied/GMC, Newark,CA

I kind of don't want to disagree with JimK, but please notice that he wrote "Should".
This is probably the expectation for barrier hose. It does not include what new "stuff" will be added to "motor fuel" in the future.

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

 

[jim kanomata1]

Yes, I do not want people to feel that the all steel line is a must.
When I do an Appraisal, on a coach, the metal hose will not add much.
We need to inform owners that the old hoses and rubber components must be
replaced.

On Wed, Feb 19, 2020 at 6:11 AM Matt Colie via Gmclist <

> > For people that want to not go to the metal way, the new rubber hosed
> > should last 25 years.
> > if your young and plan on using the coach for 25-35 years, go for the
> metal.
> > --
> > Jim Kanomata
> > Applied/GMC, Newark,CA
>
> I kind of don't want to disagree with JimK, but please notice that he
> wrote "Should".
> This is probably the expectation for barrier hose. It does not include
> what new "stuff" will be added to "motor fuel" in the future.
>
> 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
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[Matt Colie]

> Yes, I do not want people to feel that the all steel line is a must.
> When I do an Appraisal, on a coach, the metal hose will not add much.
> We need to inform owners that the old hoses and rubber components must be replaced.
> --
> Jim Kanomata

Jim,

You will not get any argument from me on that - At All - Ever.

I read a bunch of other RV sites and a thing I see all the time is that someone has bought a 20yo SOB. I runs great, but they want to remodel the
interior (and some times repair "a little water damage".
"But Hey, the tires look real good!" Then you hear one blew out.
Then I write all about how the life of any rubber thing is limited and 20 years is all you can hope for at best. They should start by changing out
all the rubber parts that they can, including the coolant and brake lines.

Keep it up Jim, the world needs you.

I would love to know what the real service life of Gates Barrier hose is, but now of mine has shown any signs of trouble - yet.

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

 

[jim kanomata1]

Matt,
I need to reach out to our factory rep and see what he says.
If the regular hose lasted 25 years , I’m assuming the barrier hose should
do the same.
Hope to see you and Mary in LA.

On Wed, Feb 19, 2020 at 10:15 AM Matt Colie via Gmclist <

> > Yes, I do not want people to feel that the all steel line is a must.
> > When I do an Appraisal, on a coach, the metal hose will not add much.
> > We need to inform owners that the old hoses and rubber components must
> be replaced.
> > --
> > Jim Kanomata
>
> Jim,
>
> You will not get any argument from me on that - At All - Ever.
>
> I read a bunch of other RV sites and a thing I see all the time is that
> someone has bought a 20yo SOB. I runs great, but they want to remodel the
> interior (and some times repair "a little water damage".
> "But Hey, the tires look real good!" Then you hear one blew out.
> Then I write all about how the life of any rubber thing is limited and 20
> years is all you can hope for at best. They should start by changing out
> all the rubber parts that they can, including the coolant and brake lines.
>
> Keep it up Jim, the world needs you.
>
> I would love to know what the real service life of Gates Barrier hose is,
> but now of mine has shown any signs of trouble - yet.
>
> 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
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[terry1]

I also have a question regarding the fuel tanks. I am taking mine down to replace the hosing, and wonder if, after I release the straps, will the tank
tip down on an angle and come out or is the flange on the tank going to catch the frame? Or do I need to also unfasten the bracket that the straps are
mounted on and drop it straight down?
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[Bruce Hart]

The straps are attached to the tanks. You will have to remove the three
screws that hold the bracket in place. If you have a floor jack and a
square piece of 2'x2' piece of plywood you can ease the tanks down after
loosening the bracket and J bolts.

On Sat, Feb 22, 2020 at 4:06 PM Terry via Gmclist
wrote:

> I also have a question regarding the fuel tanks. I am taking mine down to
> replace the hosing, and wonder if, after I release the straps, will the tank
> tip down on an angle and come out or is the flange on the tank going to
> catch the frame? Or do I need to also unfasten the bracket that the straps
> are
> mounted on and drop it straight down?
> --
> Terry Kelpien
>
> ASE Master Technician
>
> 73 Glacier 260
>
> Smithfield, Va.
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class

 

[LQQKatJon]

Terry- Straps are attached to the tanks.

you will take the 3 bolts that go through the cross member into the angle steel piece on the tank(attached to tank) out. Then take the 2 nuts off
the j-hooks, and it will drop down a little bit. the filler hose will keep it kinda up there, and you will have to tip it down and pop it to the
side to release it from the filler tube, then it will come down, and you can then worm up and get to the rubber hoses.

you have to take rear tank down, then the forward tank if I remember and usually install in reverse order.

installing, you will again fight a little to get the filler hose on and pop it into the filler hose then lift up. you want to get the J-hooks into
the straps 1st, and put the nut on by just a thread. then lift it up and the 3 bolts will line up in the cross member.

tranny jack works well, as does taking the time to set up a sling system with ratchet straps. I use harbor freight 4 wheel dolly, and let them fall
onto that, and can then roll them out from under the coach.

main thing that you want to be sure is to get all the fuel out if you can. or be prepared for the fuel to either slosh to one side making that side
heavy quickly and the weight shift bad and it gets awkward handling, or worse the fuel sloshes toward the filler tube side, and that side gets heavy
fast, and then covers you in gas. so jack the coach up a little and get all the fuel out of the drains. When I have done this job, I like using an
electric fuel pump and pump the tanks dry. that seems to get 99% of the fuel out, better then just trying to use the fuel drains.
--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[terry1]

Thanks Bruce & Jon, I figured I was going to have to take that bracket off, but wanted to make sure. My tanks are over 6 feet off the ground and I'll
use the rolling jack on the lift to catch the tanks. I ran the fuel down as far as I dared but there is always leftover fuel, right now the gauge says
1/4. At least it's not a full tank with a faulty pump in there! I'll probably get a siphon going after I disconnect the feed line from each one.
That's the second time I've read to do the rear first, so even though that looked counter intuitive I will have to check that out again.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[terry1]

O I C...It wasn't my analysis of the scenario that was faulty, it was the memory of the main&aux vs. front&back that left me...must have run off into
the woods when CRS started making visits to my head :?

Looked like a metal line coming from the rear tank anyway so problem may not be there. Must be 45 hose clamps on this Rube Goldberg looking setup
:lol:
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[LQQKatJon]

I probably have them backward. I am only pulling tanks out of a gmc every few years and I guess last time was a few springs back. I just know one
blocks the other, like said above.

Make sure you replace with good quality stainless hose clamps and tighten them tight. Fuel lines will shrink and a cheap, not tight clamp will leak.
Or at least that has been what I have seen. Don't use harbor freight clamps.

There are quite a few hose clamps needed.
--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[Ken H.]

As much as I like the screw style "aviation" clamps, I've got to admit that
spring clamps are more "durable" -- if tight enough when first installed,
they'll remain tight as the underlying hose shrinks -- no retightening as
may be needed with any screw clamp. It may even be that the much smaller
cross section, where sealing force is applied, allows them to seal better.

Ken H.

On Sun, Feb 23, 2020 at 11:55 AM Jon Roche via Gmclist <

> I probably have them backward. I am only pulling tanks out of a gmc
> every few years and I guess last time was a few springs back. I just
> know one
> blocks the other, like said above.
>
> Make sure you replace with good quality stainless hose clamps and tighten
> them tight. Fuel lines will shrink and a cheap, not tight clamp will leak.
> Or at least that has been what I have seen. Don't use harbor freight
> clamps.
>
> There are quite a few hose clamps needed.
> --
> Jon Roche
> 75 palm beach
> EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>