Auxillary Gas tank install

Here is a How To description on the installation of a second gas tank located in the area occupied by the stock spare tire.

Auxiliary Gas Tank

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I have found a solution for adding an auxiliary gas tank to my Commander. There is a business that is dedicated to performing this modification. I have purchased two auxiliary tanks in the past for different motor homes. I went by and talked to the owner this morning. When I first asked he said that he would not do it because there were several reasons not to do it on a late model gas vehicle. After he realized that I had bought two tank installations from him and we talked for awhile he came around and said he would do it just for me. I also got him to agree to put together complete kits that he would ship out of California. I talked with Ross about "Get Lost 4x4" becoming the dealer for these kits.

Now some of the details and resolved problems. The first reason he said that he did not want to install the second tank is because of an interesting fact about newer vehicles. He told me that the Commander has a small air compressor that is controlled by the computer that compares the fuel level from the sensors to the pressure reading from the compressor that puts air in the tank. The computer compares the pressure to the amount of fuel in the tank. This is why we get the engine code if the fuel tank cap is not sealed. He said that this code does not hurt anything and can be erased by removing the ground cable from the battery. Even better he said that if I get the code he will install ball valves in the filler lines to eliminate the code. The details of the setup include a 20 to 25 gallon tank in the spare tire location, a skid plate under the gas tank, using the same filler for both tanks by installing a "Y" connector, installing a second fuel gauge, and a switch up front.

The way the system will work is to allow filling from a common filler, the back tank will have a sending unit for the second gauge and a pump controlled by the front switch to recirculate the fuel from the rear tank to the front tank. A second line between the two tank will allow the fuel to circulate back to the rear tank if the front tank is full to eliminate any possibility of pumping gas out of an overful tank. Each gauge would show the level of fuel in each tank. The combined fuel capacity would probably be between 37 and 42 gallons. He also agreed to let me take pictures of the install and all parts to post on the Forum. This fellow has several Cherokee's that are set up for off road use.

Sorry for the long post.

I now need to get my tire relocated out of the spare area and mounted on a tire carrier and give him a couple of days to install it.
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2007Jeep Green Limited
4.7 Flex Fuel, Rocky Road 2.5" Lift on front, 4 inch Superlift coils on rear, Spidertrax 1.5" Spacers, Bridgestone 265/70/17
Chrome Nerf Side Bars, K&N CAI, Flowmaster muffler, Aluminum Diamond Plate Locking Trunk installed
Factory Roof Pod, Blue Ox Baseplate w/D-rings, "Get Lost 4X4" Front Bumper, T-Max 9000 winch, "Get Lost rear tire carrier, 30 gal second gas tank.
Did anyone else read the fine print in the brochure and get a $500 rebate for being a Veteran?

Update:

They started this morning at about 7:30. They are sure that it will be at least a 25 gallon tank. I am staying at a Hotel nearby because they will take all day and part of tommorow. They will put together a kit for "outside California" that will be complete. I anticipate that Ross will be able to add this to his product line. I asked them to take pictures and left my camera with them. The tank will have a skid plate under it. It may run off both tanks until the back tank get to a lower level and then I can pump the back tank into the front tank. They will each have gas guages. With an additional blitz can on the back I should have close to 50 gallons of fuel for exploring the back country.
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I am going to let Ross respond to the pricing issue. Tomorrow we should know what the kit full of parts will cost and Ross can decide how to proceed. I am just the facilitator for getting this kit available. This is kind of like a "Black Stealth" project where it is being done. The owner does not want to admit to installing it for me. The Kit is not illegal or anything and he is installing it on an out of state car, (my Commander) from Vermont.

New Update: He just called and said it is going very easily, no problems. Because of the connections between the tanks he does not need to split the fuel inlet line. He says the rear tank will fill first and then it will continue the fill the front tank. He is mounting the gauge to the right of my right knee under the dash and the switch will go in the console.

The tank will have a full skid plate. He said that he has taken many pictures.

The plan right now is to fill it in the morning about 9:00 AM and see how much it holds.
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I have not confirmed this yet, but I expect that I might get some really interesting results on the computer readout for both mileage and range. If the top half of the fuel tanks are linked as a common tank and the input for fuel tank level is comoing from the front tank sensor only, then the computer may calculate mileage and range on unreal numbers. I suspect that I will be able to photograph readings on the dash that will amaze you. They will not be real, but they might be interesting. I imaging that it might show double the MPG's and also inflated Miles to empty. Will see what happens, probably a learning curve on how to use this setup.

With this much gas onboard I might just have to ditch my JATO boosters.

Quote:
Originally Posted by JeepDog
what would be the additional weight and wouldn't that cause sway issues?


I do not expect any sway or handling issues because of several factors. The third row seat weighed close to the same amount and it is gone now. The new weight will be at the axle level and will have much less effect than say 150 pounds on the roof rack. The spare was in this area before the fuel tank. I imagine that the movement of the spare to the tire carrier had more of a negative effect on the center of gravity than the gas tank will. The gas tank should actually lower the center of gravity of the entire Jeep. I also suspect that the new tank is baffled, but I have not verified this.
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Quote:
Originally Posted by udoxx
Nonetheless 700-800 mile range if you are getting 14-16 mpg, simply amazing! That will cover a one way trip to LV from the Bay Area on one tank!

I guess if the weight is going to be an issue one can always upgrade to the OME heavy duty rear springs that support a heavier constant load.

I am glad to hear that it would be armored! I would like to know for sure if it is baffled but the only thing that is a downer will be how the computer handles the extra fuel and calculations...crossing my fingers!

I am not worried about the computer calculations. I will still have two gauges to show me how much gas I have. Funny how we survived before we had a computer to tell us how many mile to empty we had. I am looking forward to a display that tells me I am getting 40 miles to the gallon, even if it is faulty information. Might be the source of a good practical joke on someone riding along. Maybe make up a story about having solar panels on the roof or something like a hydrogen boost system.

Ok, I have lots of new information on the project. It is done, I picked it up this morning and we took it to fill the tank and check it out.

First, The tank is going to be called a 25 gallon tank, but it actually holds close to 30 gallons. This gives me 50 gallons, 55 with the gas can on the back included.

The tank is custom made out of aluminized steel and it has two baffles, brackets especially for the Commander and ports. It also has a drain in case we ever have to drain a bad batch of gas.

The fill system is really slick. The filler tube was cut and turned to fill the back tank. The filler hose from the front tank was left attached at the tank and was turned and connected to the back tank. This way the back tank fills and overflows into the front tank while you are filling it. The tanks are connected directly for the first half tank or so. When the front tank gets low you turn a 15 minute timer mounted on the console and the back tank pumps gas to the front tank. With the double connection the front tank will overflow back into the rear tank if it is too full. There is now a second fuel gauge mounted under the dash. The rear pump is a heavy duty externally mounted transfer pump.

There has been no effect on the check engine light or on the computer MPG. What does change is that because the back tank flows into the front tank it tends to keep you front tank full and my distance to empty either stays the same or might increase a little. It is just like topping off your tank at every station yoou pass.

Here are some of the pictures:

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First steps in building the tank with two baffles:

More Pictures:


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This picture show the connections. The gas goes from the filler tube into the large port on the right and then goes into the port on the left that is directly connected to the front tank. They used the existing filler hose to make this connection. The main filler tube was turned and connected to the back tank.

The brackets are for hanging the tank using "J" bolts that are hooked into the frame. The tank install was very easy, just drill four holes for the "J" bolts to hook to. The other tubes are for the vent lines and the hole is for the sending unit for the gauge. The bottom has a drain.
https://theultimatejeep.com/images/i...0/06/273-2.jpg
https://theultimatejeep.com/images/i...0/06/274-2.jpg

More Pictures:

These pictures show the transfer pump and the four "J" bolts locations. The transfer pump is on a timer in case you forget to turn it off. It would just circulate anyway but the pump should not run all the time like if you forgot a switch was on.

https://theultimatejeep.com/images/i...0/06/275-2.jpg

Left rear "J" bolt:
https://theultimatejeep.com/images/i...0/06/277-1.jpg
right rear:
https://theultimatejeep.com/images/i...0/06/278-1.jpg
right front:
https://theultimatejeep.com/images/i...0/06/279-1.jpg
left front:
https://theultimatejeep.com/images/i...0/06/280-1.jpg

more Pictures:

The departure angle is not reduced as you can see by looking at the rear frame rails.


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Here you can see the left side of the tank. The transfer pump, the inlet hose and the two "J" bolts installed to hold the tank.


https://theultimatejeep.com/images/i...0/06/285-2.jpg

more pictures:

Here you can see really well how the fuel filler works. The rust colored tube is the original filler tube turmed to the right, (it used to go to the left). The large hose at the bottom of the picture with a clamp on it takes the gas from the back tank into the original port in the main tank.

https://theultimatejeep.com/images/i...0/06/288-1.jpg

Skid plate welded under a similar tank:
https://theultimatejeep.com/images/i...0/06/289-2.jpg
https://theultimatejeep.com/images/i...0/06/290-2.jpg

On the way home I got a red Blitz can at 4 Wheel Parts for about $70. I found a surplus store down the road and got the Nato OD Green can for $30. Which one do you think I will use?

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more pictures:


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https://theultimatejeep.com/images/i...cropnato-2.jpg
https://theultimatejeep.com/images/i.../cropred-2.jpg

They made the kit so that it includes everything that you need. Hanging the tank was very easy. Drill four holes to hang the tank and connect the lines and the pump. Then wire the timer, pump and the gauge.
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Ross is working on the price. By the way I have no financial interest in this product. I just wanted to make sure that we could have a complete kit solution that will fit all of our Commanders.

I can tell you what is involved in the installation. First you remove the spare tire and the spare tire cable. You next remove the sheild that is located in the passenger side forward area of the spare tire. I am not sure if this is necessary, but they did remove mine. You would next mount the transfer pump to the unibody on the drivers side. The filler tube is then turned to the right to connect to the new tank. The filler hose from the main tank is used to connect to the new tank for transferring during fueling. There are several vent hoses that will connect when you put the tank in place. It looks like all of the connections are made behind the axle and are easy to get to. You do not have to drill into the main tank and I had 3/4 of a tank when they installed the second tank. The mounting of the new tank involves drilling four holes in the unibody panel to allow the "J" bolts to hook into the holes. The four bolts hang down and you use them to hang the tank. They fit into the four reinforced brackets and are secured with two nuts for each hanger bolt. I would think that you would want help installing it and maybe a transmission jack or some kind of support while installing the tank. The last part is running the wire for the timer and the gauge. I would wire the pump before the tank is in place. I will ask the manufacturer of the kit to put together more complete instructions and I will send them the pictures that they took on my camera for me.

I could have done this install, especially after seeing the pros do it, but it is easier for me to sit back and watch. Since I had open heart surgery I have trouble laying on my back to work under any vehicle.
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Quote:
Originally Posted by wmjacobsjr
Huey, the tank is very nice and the tire carrier looks really great with the plate light and the green can on the back. Have you had any issues with where they placed the pump switch?


Thanks, The pump switch is not in the way at all and it is a timer that you have to twist to set it for up to 15 minutes so there is no danger of turning it on accidently. Even if you could it turns itself off. It is acutally a large 110 volt timer like you would put on a hot tub, however you cannot see the back part of it. These guys really knew what they were doing and the timer was a nice touch to insure that the pump only ran 15 minutes.

I do like that NATO can also and I repainted it with OD Green paint. I used a strap to make it tight and a cable lock to keep it there.

I am looking for a stainless steel continental ring to go over the spare tire and a plastic or fiberglass disc to paint the matching "Jeep Green Metalic" color.
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I just went outside as the sun was going down and got some new pictures of the NATO can and also I took some to show that the back is still at least level. It has both tanks full right now.

https://theultimatejeep.com/images/i...06/00320-1.jpg

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Update on the second fuel tank.

I have put over 400 miles on the Commander since installing the second tank and here are some of the statistics and results.

Last night the two gauges were each reading 1/2 tank, so I have reached the point where the back tank is no longer feeding the front tank automatically due to gravity. I turned the timer on and the back tank transferred gas to the fromt tank. After transfer the front tank is now full again and the back tank has just under 1/4 tank. The shows that the overflow of fuel returned to the back tank.

Based on the remaining fuel I believe that I have a range of between 700, (easy), and 800, (pushing it) miles on the two tanks. Since my tires are larger than stock I actually have another 5% or so different than the computer calculated miles, (so 735 to 840 miles). Even with this range the miles to empty from the computer would still keep you out of trouble. The extra 5 gallons on the back will be for anyone else that needs gas. I am getting between 14 and 15 miles per gallon.

One other intresting fact. The other day while coming back from town, I looked at the main gas gauge and it was full. A few minutes later I heard the warning tone and looked down. The gauge read empty and the check engine light was on. I pushed distance to empty button and it said "0". I knew that I had a full tank. When I got home I did two things. I loosened the gas cap and felt a whosh of air going into the tank. It seemed to have a vacuum in the tank. I also disconnected the ground cable from the battery for a few minutes. I restarted the Commander and everything was back to normal, full tank, no check engine light and a reading of 328 miles to empty. Jake at the gas tank place had said that I might get a vacuum condition in the tanks and maybe that is what happened. It only happened that one time, and I will see if it reoccurs.

After filling it a few times and recording accurate odometer reading I will post more accurate numbers.

Quote:
Originally Posted by Ahmed
I'm really interested to make such a project.

Questions,

What are those small pipes at the top edge of the tank for?

What is the maximum range for the two tanks combined?

The Aux tank has the same kind of connections as the main tank. The connection at the top include a sending unit for the gas gauge, a pickup tube with a sock type filter, and lines for the transfer pump to send fuel to the main tank as well as return lines from the main tank in case it overfills. For the first 1/3 to 1/2 tank the two tanks have a common hose that allows the gas to gravity fill the front tank. The timer switch can be used to refill the front tank from the aux tank by using the transfer pump.

The maximum range depends on your gas mileage. The aux tank adds a little over 30 gallons to your capacity. I also carry a NATO 5 gallon gas can. It is mostly for helping someone else that needs gas. Good way to make friends on long trail rides.

The fellow that made my aux tank is located in California and is willing to sell the entire kit for out of state use. I think that he has one kit made up and in inventory now. I have no financial interest in his business.

I recall that it cost me $1,000. for the setup. I do not think that Ross is distributing the kit so PM me if you want more details.
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In this picture you can see that I did find a chrome ring for my spare. It came with a white disc that I painted with a can of factory matched paint and the NATO can is now OD Green.

https://theultimatejeep.com/images/i...09/00817-4.jpg