M1008 - Auxilary fuel tanks

[bshupe]

Hello -
I have looked the best I can through the forums here and haven't seen anything about adding aux. fuel tanks to the M1008.

So my questions are basically pretty standard....

Has anyone done this conversion/add-on? If so, are there any pit-falls to avoid?

Anything specific that is a must-do do in this process, parts that are best etc?

I would like to abandon/remove the factory saddle tank. Is this going to cause any major problems that anyone can think of?

If removing the stock tank is not advisable then does the aux tank feed the stock tank by gravity or, would I have to install a switching system with secondary fuel gauge etc. etc. to build a dual tank set up?

I guess what Im saying is that Im firmly at square one on this and anyone who has done this, knows someone who has done this and is willing to share some pointers would be very helpful.

Thanks!

 

[73m819]

Just find a 80s 3/4 chevy civi duel tank truck in a junk yard, get the tank, switch, other parts, the switch will change tanks as well as gage

 

[bshupe]

I like that idea although I really want to abandon/remove the stock tank and go to a 60 gallon cell in the bed behind the cab. The dual tank set-up would only be if I had to keep the stock tank for some reason which is a great play but too much complexity for my final goals with the truck.

Thanks for taking time to reply!

 

[73m819]

If that is the case, dump the stock tank, get the correct OMM reading after market sending unit for the back tank so the gage reads correct, easy install, I used to run a 50 gal. back tank

 

[idM1028]

Technically, you're not adding an auxiliary tank, you're relocating the position of the tank and adding a bigger tank, but whatever, I'll bite. As far as a tank I'd probably go with this or something like it: RDS Auxiliary Fuel Tank — 60-Gallon Capacity, Model# 72771 | Auxiliary, Transfer, + Skid Tanks | Northern Tool + Equipment As far as mounting it in the bed, I'd just probably weld some pretty beefy tabs on it and bolt it directly to the bed. That and add a locking fuel cap so nobody can just waltz up and siphon my fuel. You shouldn't have to worry about a fuel pump since the 6.2 already has it on the engine block. You are however, probably going to have to find a fuel level sensor and put that in somehow. Just out of curiosity, what are your goals with this truck?

 

[M1031CMT]

If you don't mind loosing the under-body mount for the spare tire, you could get an in frame fuel tank from an older suburban and put it back there to start. You just need to weld in some brackets, but they fit (basically the exact same frame). Then put an additional tank in the bed. That would clear the frame for you if that is what you want/need to do.

 

[biggestc69]

Does anyone know of an aftermarket larger fuel tank that will work in the stock location?

 

[bshupe]

Technically, you're not adding an auxiliary tank, you're relocating the position of the tank and adding a bigger tank, but whatever, I'll bite. As far as a tank I'd probably go with this or something like it: RDS Auxiliary Fuel Tank — 60-Gallon Capacity, Model# 72771 | Auxiliary, Transfer, + Skid Tanks | Northern Tool + Equipment As far as mounting it in the bed, I'd just probably weld some pretty beefy tabs on it and bolt it directly to the bed. That and add a locking fuel cap so nobody can just waltz up and siphon my fuel. You shouldn't have to worry about a fuel pump since the 6.2 already has it on the engine block. You are however, probably going to have to find a fuel level sensor and put that in somehow. Just out of curiosity, what are your goals with this truck?

Big picture - Crunch rig. Haul water via tank in bed and/or trailer, haul produce or other supplies after initial shock and fall-out of local or national crisis. Our group is the bug-in variety for many well thought out reasons and we all came to the conclusion that we needed a vehicle for post -whatever- and this is what we landed on.
Short/medium term - snow vehicle, light 4x4 recreation and minor hauling etc. Basically I want to keep it in some kind of regular service to keep everything fresh. Nothing worse than letting the thing sit a long time and then try to put into service.... but then all of you know that already.

The tank is primarily to add range. Where I live, I have no practical way to store any amount of fuel much less a deep reserve so I want the truck to have that capability. I dont like giving up payload but I want/need the added capacity. I hope to regain the lost payload via a similar vintage trailer.

Thanks for the link, that mfg seems to be the most prominent (on the web) and they have some very nice variations with great reviews from RVers and such. A little pricey but that may just be the cost to play.

Sorry if thats a little long winded but you asked.

 

[TXM1009]

I have a 60gal aux tank in my pickup that feeds the main tank via gravity. It sits in the bed behind the cab and has a small tool box in the top of it. I think they are only approved for diesel. I have had it for several years now with no issues. I think it is an RDS. Not sure if you could get it work with your fuel gage though.

There are some companies that make over sized fuel tanks, but not sure if any of them offer them for these older trucks

 

[M1031CMT]

Does anyone know of an aftermarket larger fuel tank that will work in the stock location?

Never heard of a larger one. And I think a larger one might cause clearance problems where it sits between the frame and cab and any equipment you might have installed. Any longer or lower and the tank will likely get smacked going off road. Though that doesn't mean large tanks don't exist.

One thing you can do is install dual saddle tanks. Trucks are designed to take another tank on the drivers side. I have a gasser M1008 (military up here initially bought trucks with the 350 engine in them) which originally had dual tanks (previous owner pulled one off after the tank straps rusted out). But I still have the fuel tank selection switch on the dash. You can find the dual tanks on a lot of the civilian 1ton trucks in the scrap yards.

 

[bshupe]

I have a 60gal aux tank in my pickup that feeds the main tank via gravity. It sits in the bed behind the cab and has a small tool box in the top of it. I think they are only approved for diesel. I have had it for several years now with no issues. I think it is an RDS. Not sure if you could get it work with your fuel gage though.

There are some companies that make over sized fuel tanks, but not sure if any of them offer them for these older trucks

I guess if it was feeding the stock tank I wouldnt need a separate gauge for the aux. tank. I am hoping to remove the stock tank if it doesnt cause me too much grief so then it would just be a matter of getting an appropriate sending unit for the larger tank.

Does your RDS tank have a sight gauge on it? If they do I could just have one of my kids ride in the bed and call out numbers as it goes down. Maybe hand signals in the winter. lol

 

[TXM1009]

Mine does have a "float" gauge I guess it would be called, but it is under the tool box lid. I have seen some, I think the newer models where the gauge is outside the lid. With my setup and the existing tank, I know when the fuel gauge starts moving away from full that the bed tank is empty.

 

[TXM1009]

Out of curiosity why do you want to remove the existing tank. I like to have all the fuel I can get. Especially if I'm towing something heavy. I want to see if I can get a 40gal suburban tank under my m1009.

 

[bshupe]

Out of curiosity why do you want to remove the existing tank. I like to have all the fuel I can get. Especially if I'm towing something heavy. I want to see if I can get a 40gal suburban tank under my m1009.

Mostly for safety and reliability. i realize that diesel is pretty safe as fuels go but that is just a terrible place to have a tank and in even a minor collision you could be completely disabled by a punctured/ruptured tank.

If it ends up being too big of a hassle to remove it then I may do the gravity feed to the main tank from the back and add some of those great rock sliders I saw in one of the other threads on here.

 

[doghead]

Are you concerned with what is legal? Those tanks are not legal as a main tank. Gravity feeding your stock tank is probably not legal either(check your state laws).

An extra 100 gallons of fuel along with the stock tank, weighs in at about 1/2 a ton. If you need to add a water tank, your going to be limited to about 120 gal tank for that.

Having a large tank full all the time, will promote algae and fuel issues.

Are you really that worried about getting T-Boned and still being able to drive for 300 miles after that?

 

[unaffiliated]

If I were you, I would add a factory auxiliary tank on the passenger side, then a factory rear mount 25 gallon tank (LMC Truck part # 32-5943) where the spare tire goes. That way you would have 65 gallon capacity and still be able to use the bed. I'm thinking that in a SHTF situation, you are gonna want all the hauling capacity you can get, but that's just me thinking out loud, what do I know. Look at the stats on the fuel tank safety. Of the millions of these type trucks built, I would say only a very small percentage were ruptured. If it were that big of a problem, GM would not have put them there for almost 20 years. Besides, most likely diesel will not ignite like gasoline will in a spark situation. Just my humble opinion.

 

[doghead]

Of the millions of these type trucks built, I would say only a very small percentage were ruptured. If it were that big of a problem, GM would not have put them there for almost 20 years. Besides, most likely diesel will not ignite like gasoline will in a spark situation. Just my humble opinion.

Actually, it was a big deal. GM Fuel Tanks Pickup Truck Class Action Lawsuit - LieffCabraser.com

Google "chevy truck fuel tank lawsuit".

 

[unaffiliated]

I'm familiar with the lawsuit. I actually got a settlement on a 78 Chevy pickup I still own (parts truck). They awarded me $100 towards the purchase of a new truck. WOW, how generous. The award was not redeemable for cash, and I could not afford a new truck, so I was SOL. I looked at your link and it said the award was $1000, but mine was only $100. I probably still have the paperwork somewhere. I still think that only a small percentage of of the 10 million truck's tanks were ruptured or they would have recalled all of them and installed a plastic tank.

 

[100acre]

aux tank

I was working on the same idea premise and recently purchased a 75 gal 939 series fuel tank for the bed to increase milage and to store wmo blends for the long haul. There will undoubtably be many sitting vehicles with diesel and oil /trans fluid all over the place. My idea is to have a mobile filtering station in one of my trailers. If one were to have a 75 gal, 2 stock, and 1 suburban ( mounted in spare tire well) tanks. I believe you could travel up to 1500 miles without refueling. Of course you will be a major target when all other vehicles are kaput

 

[rickf]

I guess if it was feeding the stock tank I wouldnt need a separate gauge for the aux. tank. I am hoping to remove the stock tank if it doesnt cause me too much grief so then it would just be a matter of getting an appropriate sending unit for the larger tank.

Does your RDS tank have a sight gauge on it? If they do I could just have one of my kids ride in the bed and call out numbers as it goes down. Maybe hand signals in the winter. lol

You say you are looking for maximum fuel storage correct? Why do you want to remove the stock tank if you put one in the bed? That is 20 more gallons you can carry and it is in a place where it is out of the way. I have a 75 gallon tank in my Dodge that gravity feeds the stock tank. You have to have the kit that is made for this so you do not overflow the stock tank. If you go with the aftermarket only be aware that you will have to plumb the fuel return lines to it. The fuel return always has to go to the tank that is in use.

Rick