Guys, I'm looking for some advice on installation of an aux fuel tank (truck box mounted). I'm looking at having a local guy weld up an aluminum "box" for me. I've seen many other guys hookups to their main tanks. Some have a vent on the aux tank and bring a single fuel line from the bottom of the aux tank into the main tank filler hose. I've seen fuel pumps, solenoid valves and plain old manual taps to operate the refilling action.

I've been told though that the main fuel tank is pressurized and that I have to maintain that with the aux tank. That means a sealing fuel cap and 2 hoses from the aux to the main. One from the bottom of the aux tank to the filler hose on the main and a second from the top of the aux tank to the breather hose beside the filler to the main. I plan on using this config with a solenoid activated valve so I can refill while driving.

I'm sure many of you have experience on this. Would appreciate your inputs before I do this job.

Thanks....

 

Mine is T'd into the vent line and gravity feeds into the OEM tank through a filter and solenoid valve. I'm not sure of pressurization in the new ones - not in '98 as this set-up works for mine.

 

Same here,one line at the bottom of tank approximatly two inches from the bottom of tank,then thru a filter mounted under bed on frame which is then activated by a elec. solenoid,it is slow and I have to watch gauge,but cheap and it gets the job done. Goodluck, Rick

 

Thanks guys. If you only have the one line I assume you have the aux tank vented so air can come into the tank as fuel drains. With only one line into the main tank what happens to the air that is displaced by the fuel if you don't remove the filler cap while fueling???

 

I have the transferflow. Remember what is leagle. I think it vary's from state to state. I know in NC its illegle to have a manual switch that you cut the fuel pump on and off. This is to prevent over filling of the factory tank and it spilling all over the road. Your best bet is if your wanting it cheap. Go and buy a fuel cell somewhere like Tractor Supply or Northern Tool, and put a filling pump and nozzel on it. Like at a fuel station. My 2c

Kimrey

 

Chester,
I looked at all this and settled on the RDS tank/tool box combo. You can buy it direct from the factory. Mine is hooked gravity. The 2003's are sealed tanks (cap is not vented). So, you can leave the valve open and it will not overflow. You can contact RDS at 1-850-584-6898. You can see a pic of mine on page 10 of member photos (at least you could before the update - - don't know where it is now).

If you want more details, PM me your email and I will send pics of the installation and a list of materials to do it yourself. RDS makes a nice tank, baffled, all ready with vent installed. It's now worth it messing around and getting something hashed together. Very simple installation, nothing to go wrong or burn up, no pumps to quit, no electronics. I have three other installations that cost a lot more and I am just as happy with this one. In fact, a lot happier than I was when a switchover valve stuck in the middle of Arizona and I was out of fuel.

Bob

 

I bought an Aero, Diamond Plate 45-gal in-the-bed tank a couple of years ago and I Love it. I plumbed it at first with only one line and then regretted it because of all the outside air (and dirt) which was getting sucked into the Aux tank. So I ran another line for a vent line. Both lines go to small sections of 3/8 brake tubing which are welded into the filler neck. Works great!

I do have a switch inside the cab, wired to a Green led, which lights up when the small fuel pump is flowing fuel. I also mounted a big Napa Fuel Filter/Water separator so most of the fuel gets filtered twice. I have saved some bucks with this set-up, and I can go around 1,500 miles without a fill-up if I need to.

 

I went with an Aero in bed, verticle 45 gallon aux tank on my '93. I've got a canopy so I plumbed it through the canopy right in back of the drivers side. I was able to get a fuel tank door at a junk yard that was the same color as my truck. It is plumbed through two manual valves ( 1 for fuel the other for return) which are on the floor right next to the drivers seat. I can reach down and switch them while running down the road.I decided on manual after a bad experience with an electric valve. It switched the gauge but not the tank. Luckily I was driving a gas passer. Hope this helps.

Bob

 

The air wont be displaced. I drop fuel from the aux to the main with the filler cap closed tight.The tank level remains almost static for a long time as fuel drains in.If you want it to go faster,loosen the filler cap and the air can be displaced..Mine tees into the vent line.It might not be legal but it is simple and it works....It is really nice to make road trips without having to stop for fuel.I can tow for 1000 miles or run light for 2000

 

i had 100gallon tank plumbed into my 92 250's vent tube i'll never do it again, nut'n but headache buy yourself a transfer pump and a good filter you wont be sorry, besides it only takes 5 min to get out strech and fill your tank, and its legal.

 

Thanks everyone for your information. It looks like there are a lot of different ideas on how to hook these things up. I'll let you know what I finally come up with....

 

I had one of their 60 gallon with tool box in the White Obsession. Now that it's sold and I have the New 04 (Ghost Rider), I will be mounting another 60 gallon with tool box in the bed of it.

I found that I can purchase the tank cheaper from Northern Tools than from the factory. The factory shipping cost were about $50 more.

Bob, how did you plumb you tank without any electronics? I didn't think gravity fed was legal. Let me in on your secrets.

 

Big Bob,

Sorry not answering quicker. Been gone having fun and didn't catch this post until tonight.

Gravity feed is legal here. The new tanks are all sealed. That takes the danger of overflow away. I feed into the filler tube which is full of air. That allows the fuel to flow into the main tank and air to gurgle back up the line into the aux tank. Tapping into the overflow tube will not allow that. It is a really simple installation with no pumps, no wiring, nothing mechanical except a simple flow valve that I turn manually when I want to refill the tank. I typically just run on the aux after a fillup until I see the gauge start to move. I know the aux tank is then empty. Real rocket science in that. I also note the mileage when I fill to have an idea where I am on fuel.

Hope that helps.
Bob

 

Hi Fiverbob. The tank I was looking at here to have made was going to cost almost $900 Cdn. That's way out of line. I've got a couple of other leads here. If no good I will call RDS. My main concern is clearing the border with it. These tanks are not legal here although most people with the larger fivers have one. I've got lots of time...my trailer is buried in the snow.

 

Chester,

I have a wonderful idea. As soon as you find your trailer under the snow, hook up and head south. Stop by the RDS factory (north Florida) and pick up whatever tank you want. Drive on down to God's country (mid Florida). I will get reservations for you in the State Park about two blocks from my house. You can look at my installation - - we will go get the parts, install that sucker and then you can go canoeing with the alligators and thaw out. Now, doesn't that sound like a winner?

BigBuddyBobby