Haven't been on here is a while. I like to read but don't post a lot. So found a killer deal on Craigslist that I couldn't pass up. A Gravity feed 85gal auxiliary diesel tank with baffles in it.

Did as much research as I could but still Got a few questions and know you guys can help me out. Looking at this

RDS Diesel Install Kit for Auxiliary Diesel Fuel Tank — Fits 1999–Current Ford and Dodge, and 2011–Current Chevrolet and GMC Trucks, Model# 011025 | Auxiliary-Transfer Tank Accessories| Northern Tool + Equipment

and hooking up like it shows.

except NOT putting in the shut off valve and in it's place putting in a 12V solenoid valve. With a switch on the dash to open it. Thinking that even if I forgot and left the switch on I souldn't overflow the truck tank. Think that would work?

Also... the opening at bottom of tank is 2in OD so buy one of these 3/8 Aluminum NPT Fitting and get someone to weld it on... sound OK?


Next issue is the tank vent. Looks like a 1/2 fitting... is this what I need? 1/2" Thermal Relief Rollover Vent and get a 90deg like what is on there but with a female end sticking up rather then a male end?


THANKS for your help! Just want to make sure I do it right the first time...

 

If it were me - I would have the bottom 2" hole welded shut & have a small 3/8" bung welded on the side down low. Then u can just plumb it however u want. Just install a 3/8" ball valve. When u get out to stretch every couple hundred miles just open it for 5-10 minutes. That kit from Northerm would work great to get u into the main tank.

 

that pipe nipple hanging down at the bottom might make a nice cleanout..
i would see if i could get that spout through the bed with a sturdy valve on the underside of the truck.

i kind of like the idea of just having it fill your other tank... but i would be scuured of overfill. switches arent too expensive for peace of mind... and you could still switch between tanks.

xtof

 

My father did something like this, but used an electric pump on an in cab switch from the bed tank to the truck tank (feeding into fill neck vent tube). Worked great till he forgot to turn it off when he went into walmart. Pumped diesel on the parking lot. He overfilled the truck tank and it ran out of the tank vent.

A lesson: pipe your truck tank vent back into the aux tank, then vent that tank to atmosphere. When the overfill happens, it circulates into the aux tank, and never overflows.

I would never have a gravity feed directly to the truck tank. It is not DOT legal. If the hose came undone.... there goes 100's of dollars of fuel and you are liable for cleanup costs for the spill. My father paid $6500 after insurance.

 

First, the kit I was looking at to hook the aux tank to the truck tank has, in the T, a brass (ball float type) shutoff to prevent overfilling. I am also planing on putting a 12V solenoid valve, so I am not relying on just that brass ball float shutoff. It will be there JUST IN CASE I forget to close solenoid then it still should not overfill.

Second, I don't know where you get your info from, but here it is from the DOT website.

(d) Gravity or syphon feed prohibited. A fuel system must not supply fuel by gravity or syphon feed DIRECTLY to the carburetor or injector.

If they made a law against gravity feed from tank to tank, they would just about park every 18 wheeler on the side of the road since they have a 1/2" to 3/4" equalizer line running tank to tank. Which gives us little guys a loop hole to run big gravity tanks to our little factory tanks.

Here is the website.
All fuel systems. - Federal Motor Carrier Safety Administration

 

Yeah, that is what I was planning. I think tank is going to sit up offa bed 2.5in. If I can get a 3/8" bung welded in that nipple, then a shut-off-valve (to make DOT happy unless a solenoid calve counts as a shutoff) then my solenoid and then that T fitting with the ball float type shutoff I think I am more then covered against overfilling and leaks.

 

I run a 91 gallon auxiliary tank with a Holley fuel pump and switch on the dash. After looking at the tank you have selected I would add the following to the conversation:

1. The tank looks like it will ride about two inches over the bed rail. I am not sure if this is due to the bottom outlet or not; however, it can be a PITA to find a bed cover to go over these things. If you don’t ever plan on having a bed cover then you won’t have an issue but if you change your mind, you are very limited in options.

2. Take the large vent off and put a much smaller diameter one on the side because these tanks have a tendency to toss the fuel around as you drive from point A to point B and a vent that size will have fuel all over the place. I have a small tube with a filter element out of one of my old dive regulators to keep the fuel from dripping out when you the tank is half full and you go around corners.

3. I left mine as a gravity feed tank for years before I made the switch to a Holley fuel pump. It is not a big deal to simply reach in and switch it on when you need it and turn it off a few minutes later but there are advantages to having a separate pump on a switch. I use mine for emergencies only and routinely carry an extra 50-60 gallons of diesel just in case but I still fill the main tank regularly at the gas station. About every three or four months I will cycle out the aux fuel to keep it fresh.

4. I do not see any type of fuel level indicator for the tank so you will need to keep a small notebook to keep accurate track of how much fuel you have at any given time. I have a stock 38 gallon fuel tank so each mark on the fuel gauge is roughly 10 gallons and that is how I keep track of what I am using from the aux tank. Even though my tank from northern tool has a fuel gauge, it works about as well as standard instrument gauges which are to say, it is not very accurate.

5. The one word of caution I would offer is letting the tank gravity feed if you are on a slight decline towards the driver’s side. It may sound obvious but a friend of mine parked at an angle and left his gravity feed on with the assumption that it would stop when it was filled but he ended transferring 45 gallons to the ground.

I am sure you will be happy with it whichever way you choose to run it. Many have the misconception that the fuel will enable the driver to drive non-stop for thousands of miles and while this may be true, bathroom breaks and food stops will routinely negate the non-stop concept. I’m lucky to get 2 hours on a road trip with the wife before she needs to stop anyways.

 

I have a 95 gal transfer L-tank behind my tool box in my bed. I don't want to take the chance of overflowing my truck tank, so I put a 12v pump on it to pump the fuel to my truck tank. I also use it for my tractors. I have helped a few people on the road that ran out of diesel. Here is a pic. I have a switch in the cab to turn on the pump.

 

I need one of these aux. tanks bad, its hit or miss here for used one........

 

Yeah... I have been watching CraigsList for about a year before finally finding one. I was a little limited because I have a shortbed truck. I think 85gal is about Max I can fit in there and still pull 5er. It sticks above the bed about 1in so should be fine!

 

You are correct if it is diesel. If it was gasoline, I would be correct. Same regulations as above, different line.

 

make me an offer on my transfer flow 50 gallon tank. In good shape and fully functional.

 

some people use a timer switch like the bathroom fan type,which is not full proof but could help on over fills.