Fuel Tank + AUX + Tool Storage?

[East_Bound]

What's up guys -

I realize how many aux/fuel tank threads there are on this site and am sure you guys are exhilarated for another one so here it goes...(Pics Below)

1971 Chevrolet C20 Custom Camper

So I understand the fuel filler on the cab is my main fuel tank and I understand my fuel filler on the bed is my auxiliary which holds one gallon? When I look under the truck on the driver side, I only see one big tank and not two separated. Is the auxiliary located inside the main fuel tank? How would I gain access to it if needed?

When I looked on my passenger side I thought I found another tank for fuel, but noticed on the outside there is a slot for a key, so I would assume that is the tool storage that is noted on the inside of my glove box?

And while I'm at it...My AUX Filler cap fits perfectly while my main fuel tank cap only locks on one of the tabs so I get to look really classy around town by locking it down with duct tape. Is this a cheap universal cap someone bought over time?

I found a cap online. Is this the right one?

http://www.partsgeek.com/catalog/197..._tank_cap.html

I noticed the top two caps up top look and sound identical..What is the difference? Thanks in advance!

[jocko]

1st pic is of the aux tank - it's underbed on the driver side and has its own filler neck on the bedside. the main tank is behind your seat - and the filler neck is on the cab. the switch on the floor/sill near your seat adjust lever is the selector valve for fuel flow. the switch on the dash (assuming this is an NL2 RPO truck, which it sounds like), is to select which tank's fuel qty is displayed on your fuel gauge. Caps should be different between a truck that does and doesn't have an evap system. For a 3/4 ton, I believe they did not come with an evap system.
LMC part # for cap w/o evap system = 32-4120

EDIT: btw, the link you shared for caps, those are the correct ones for a non-evap truck, like yours - any of those would be fine too.

[East_Bound]

That is a lot of great information. I was not aware that the tank underneath was the auxiliary tank. I assumed an auxiliary tank was a reserve (1 gallon) but that tank looks quite large. What is the typical capacity of the aux tank. Also does the auxiliary tank just serve to be a regular second tank or does it have a special purpose?

Originally Posted by jocko

1st pic is of the aux tank - it's underbed on the driver side and has its own filler neck on the bedside. the main tank is behind your seat - and the filler neck is on the cab. the switch on the floor/sill near your seat adjust lever is the selector valve for fuel flow. the switch on the dash (assuming this is an NL2 RPO truck, which it sounds like), is to select which tank's fuel qty is displayed on your fuel gauge. Caps should be different between a truck that does and doesn't have an evap system. For a 3/4 ton, I believe they did not come with an evap system.
LMC part # for cap w/o evap system = 32-4120

EDIT: btw, the link you shared for caps, those are the correct ones for a non-evap truck, like yours - any of those would be fine too.

[LockDoc]

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In the picture It looks to me like your fuel filler neck might have a piece broken off of it. There should be a curved area on both sides for the tabs on the cap to catch on. It looks like one side has it and one side doesn't.

LockDoc

[jocko]

agree with Leon, that's why only one of your cap tangs is hooking up. your cap may be just fine (especially if it's the one pictured - it has both tangs). I don't remember the capacity of the aux tank... 14 or 18 gal, or something like that. It is not a special purpose, per se - you just drive along on the main tank until it approaches empty on the gauge, then flip both switches (dash and floor) and drive on the aux tank until it's time to go to the gas station. That is why these trucks had an aux tank - too frequent gas station stops because these aren't exactly economy vehicles and they use a lot of gas.

[East_Bound]

That would make sense, I remember hearing something about that. Would it be possible to weld a piece onto it or even gorilla glue for it to be sealed? I can only put half a tank of gas as it will splash out. I would assume the gas tank would have to be empty of gas and fumes to be able to weld?

Originally Posted by LockDoc

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In the picture It looks to me like your fuel filler neck might have a piece broken off of it. There should be a curved area on both sides for the tabs on the cap to catch on. It looks like one side has it and one side doesn't.

LockDoc

[East_Bound]

Okay, thanks for input. Do you know where to buy the AUX filler cap? I took it off and put it on the top of truck and drove off without it right now

Originally Posted by jocko

agree with Leon, that's why only one of your cap tangs is hooking up. your cap may be just fine (especially if it's the one pictured - it has both tangs). I don't remember the capacity of the aux tank... 14 or 18 gal, or something like that. It is not a special purpose, per se - you just drive along on the main tank until it approaches empty on the gauge, then flip both switches (dash and floor) and drive on the aux tank until it's time to go to the gas station. That is why these trucks had an aux tank - too frequent gas station stops because these aren't exactly economy vehicles and they use a lot of gas.