Auxiliary Fuel Tank - The 1947 - Present Chevrolet & GMC Truck Message Board Network

doctorplastic · 09-22-2009, 06:54 AM

Hi Guys, Still trying to figure things out on my new truck. Its a 1972 Cheyenne 20 Super. The tag on the glove box states that the truck came with an auxiliary fuel tank. Currently the gas guage is not working, it just turns to one side and stays there when the truck is running. I see the label in the dash to the left of the guages, but the switch is missing. Am I correct in understanding that switch is just to switch from one sending unit to the other. No I also understood that there is a manual valve to switch from tank to tank under the drivers seat. Well I check and there is no valve...but there is hole about the size of a dime. Now we get to the main problem. The guy I bought it from said tha the took out the tank to have it clean out as it was "rusty." He wasn't able to find the tank at the time of purchase...so my question - Is it possible to replace all three of these items to keep the truck as factory looking as possible? My main concern is the tank. I figure the switch on the dash is some sort of toggle switch and the valve on the cab floor can probably be replaced with a mechanical aftermarket valve along with the missing fuel lines. Now the wiring is still there wrapped around the frame under the bed. I would also have to find a filler neck because that is missing. I know that LMC sells the rubber hose that goes from the filler neck to the tank.

I want to keep this truck as original as possible. It's a Cheyenne 20 Super like I said, with factory camper equipment (dual batteries, auxiliary tank (option), sliding rear window, and large side mirrors. It also as the posi rear end with a wood bed and number maching 402 big block. This could be a really sweet truck if I can get everything back to the way it looked when it rolled off the factory floor.

mtdave2 · 09-22-2009, 07:54 AM

is this the same number as yours?

the switch for changing between the 2 sending units in the on just above the drivers ac vent.

the tank selector was on the floor to the left of the seat, next to where your seat belt attaches. most all i ha ve seen have stopped working. i just installed an electric selector and use a toggle on the dash to select tanks.

let me know if its the same number and ill take photos of what the tank looks like.

you can see the gas cap for the aux tank in this photo..

**special-K** · 09-22-2009, 09:00 PM

WELCOME!!

Sounds like a nicely ordered truck.The kind I like.The auxilary tank is`72-only.The pieces will have to be sourced used.None are available new.
Dave shows a good example of what you`re looking for.On the inside of the bed is a square duct covering the filler tube.what the switch does is switch power to the gauge from one tank sending unit to the other.Which side of the gauge does the needle go,full?That would indicate the wire is grounded out.

doctorplastic · 09-23-2009, 11:11 PM

I hope I loaded these pics right. Here is the parts identification tag on the glove door. I also included a pic of the hole where the dash switch goes and a pic of where the filler neck should be. How do you think it would be to replace these things?

doctorplastic · 09-23-2009, 11:35 PM

Okay, so I'm guessing the files were too big...so I know this is cheesy but I uploaded them to my old myspace account and just attached the link.

http://viewmorepics.myspace.com/inde...lbumId=1403233

gregg72340 · 06-21-2010, 02:42 PM

Does anyone know how hard it would be to put one of these in a truck that didnt originally come with one?

**rbagley** · 06-21-2010, 03:48 PM

I have two auxiliary tanks, two 3-position valves to select the tank(?) and two toggle switches that don't look original and go to fuel pumps for each tank. There is no switch for the sender unit though. Did all aux. tanks have sending units or did you just have to guess on some?

Se7en Deuce · 06-21-2010, 04:23 PM

can i see some pics of your truck inside and out
I just bought pretty much the exact same truck but its in rough shape and would love to see what its supposed to look like

I think the only major diff between mine and yours is mine came with buckets

Se7en Deuce · 06-21-2010, 04:34 PM

lemme know if I can take anymore pics for you.
assuming its still there lol.

GASoline71 · 06-21-2010, 04:57 PM

Cool... my 1972 GMC 1500 Super Custom had dual reserve tanks. One on each side. and had the switch in the floor as well. You can see in the pics that there are holes on both sides of the bed near the cab where the filler necks came through. They also extend in to the bed and go through the bed floor.

But I don't have any parts for it. The tanks and all that went with them were out of the rig when I got it. The holes in the cab floor are still there where the remote tank lever mounted as well.

Gary

JointTech · 03-25-2013, 08:02 PM

sorry to bring this thread back to life but I just found out my aux tank is factory and need a new sending unit / fuel pickup for it.
Anybody know where to get one?
http://67-72chevytrucks.com/vboard/s....php?p=5955350

09-22-2009, 06:54 AM	#1
doctorplastic Registered User Join Date: Mar 2009 Location: Phoneix, AZ Posts: 9	Auxiliary Fuel Tank Hi Guys, Still trying to figure things out on my new truck. Its a 1972 Cheyenne 20 Super. The tag on the glove box states that the truck came with an auxiliary fuel tank. Currently the gas guage is not working, it just turns to one side and stays there when the truck is running. I see the label in the dash to the left of the guages, but the switch is missing. Am I correct in understanding that switch is just to switch from one sending unit to the other. No I also understood that there is a manual valve to switch from tank to tank under the drivers seat. Well I check and there is no valve...but there is hole about the size of a dime. Now we get to the main problem. The guy I bought it from said tha the took out the tank to have it clean out as it was "rusty." He wasn't able to find the tank at the time of purchase...so my question - Is it possible to replace all three of these items to keep the truck as factory looking as possible? My main concern is the tank. I figure the switch on the dash is some sort of toggle switch and the valve on the cab floor can probably be replaced with a mechanical aftermarket valve along with the missing fuel lines. Now the wiring is still there wrapped around the frame under the bed. I would also have to find a filler neck because that is missing. I know that LMC sells the rubber hose that goes from the filler neck to the tank. I want to keep this truck as original as possible. It's a Cheyenne 20 Super like I said, with factory camper equipment (dual batteries, auxiliary tank (option), sliding rear window, and large side mirrors. It also as the posi rear end with a wood bed and number maching 402 big block. This could be a really sweet truck if I can get everything back to the way it looked when it rolled off the factory floor.

09-22-2009, 07:54 AM	#2
mtdave2 newly minted old timer Join Date: Dec 1999 Location: Hudson WI Posts: 3,507	Re: Auxiliary Fuel Tank is this the same number as yours? the switch for changing between the 2 sending units in the on just above the drivers ac vent. the tank selector was on the floor to the left of the seat, next to where your seat belt attaches. most all i ha ve seen have stopped working. i just installed an electric selector and use a toggle on the dash to select tanks. let me know if its the same number and ill take photos of what the tank looks like. you can see the gas cap for the aux tank in this photo.. __________________ ____________________________________________ 72 c20 longhorn 65k org miles and counting! 69 k10 Suburban Last edited by mtdave2; 09-22-2009 at 08:00 AM.

09-22-2009, 09:00 PM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: Auxiliary Fuel Tank WELCOME!! Sounds like a nicely ordered truck.The kind I like.The auxilary tank is`72-only.The pieces will have to be sourced used.None are available new. Dave shows a good example of what you`re looking for.On the inside of the bed is a square duct covering the filler tube.what the switch does is switch power to the gauge from one tank sending unit to the other.Which side of the gauge does the needle go,full?That would indicate the wire is grounded out. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

09-23-2009, 11:11 PM	#4
doctorplastic Registered User Join Date: Mar 2009 Location: Phoneix, AZ Posts: 9	Re: Auxiliary Fuel Tank I hope I loaded these pics right. Here is the parts identification tag on the glove door. I also included a pic of the hole where the dash switch goes and a pic of where the filler neck should be. How do you think it would be to replace these things?

09-23-2009, 11:35 PM	#5
doctorplastic Registered User Join Date: Mar 2009 Location: Phoneix, AZ Posts: 9	Re: Auxiliary Fuel Tank Okay, so I'm guessing the files were too big...so I know this is cheesy but I uploaded them to my old myspace account and just attached the link. http://viewmorepics.myspace.com/inde...lbumId=1403233

06-21-2010, 02:42 PM	#6
gregg72340 Registered User Join Date: May 2010 Location: ambler, pa Posts: 325	Re: Auxiliary Fuel Tank Does anyone know how hard it would be to put one of these in a truck that didnt originally come with one? __________________ Just would like the snow to stop so I can actually work on my truck!!!!!!!!!!!

06-21-2010, 03:48 PM	#7
rbagley Senior Member Join Date: May 2009 Location: Walla Walla, WA Posts: 319	Re: Auxiliary Fuel Tank I have two auxiliary tanks, two 3-position valves to select the tank(?) and two toggle switches that don't look original and go to fuel pumps for each tank. There is no switch for the sender unit though. Did all aux. tanks have sending units or did you just have to guess on some?

06-21-2010, 04:23 PM	#8
Se7en Deuce Registered User Join Date: Jan 2010 Location: Covington, WA. Posts: 55	Re: Auxiliary Fuel Tank can i see some pics of your truck inside and out I just bought pretty much the exact same truck but its in rough shape and would love to see what its supposed to look like I think the only major diff between mine and yours is mine came with buckets __________________ Currently Owned: 71 cab 68 swb frame and bed 67 front clip 350/t350- posi 373 rear end

06-21-2010, 04:34 PM	#9
Se7en Deuce Registered User Join Date: Jan 2010 Location: Covington, WA. Posts: 55	Re: Auxiliary Fuel Tank lemme know if I can take anymore pics for you. assuming its still there lol. __________________ Currently Owned: 71 cab 68 swb frame and bed 67 front clip 350/t350- posi 373 rear end

03-25-2013, 08:02 PM	#11
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: Auxiliary Fuel Tank sorry to bring this thread back to life but I just found out my aux tank is factory and need a new sending unit / fuel pickup for it. Anybody know where to get one? http://67-72chevytrucks.com/vboard/s....php?p=5955350 __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread



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