Auxiliary Tanks « 4xforum.com, the 4×4 Info-Tainment Channel

Auxiliary Tanks

Fuel tanks

Easily fitted to most 4x4s, these are the best way of increasing vehicle range in a safe, odor free way. But, some materials used in the construction of fuel tanks, even by reputable safari equipment manufacturers, is ill-advised. Stainless steel is brittle and should not be used for any tank, fuel or water, that is bolted to the chassis, Because every chassis is designed to flex, any tank bolted to it will flex to a degree. If it does not, it will damage the the chassis, if stainless steel flexes, it tends to crack! Don’t the makers of these tanks know this? The position of tanks will vary from vehicle to vehicle. possible locations are under the front wings, under the seats, in the loading bay as far forward as possible (pick-ups), headers above the existing tank, alongside the chassis rails between chassis and outer body near the doors and on the floor of the loading area. Never install a fuel tank in front of the engine-spillage or leakage can cause a disastrous fire. Switching from one tank to another can be made using either electronic solenoid valves or taps, the former being more expensive, or individual fuel pumps. Be aware that electric diesel pumps are notoriously unreliable. It is important to use proper fuel hose when fitting tanks as ordinary hose will soon become brittle and crack. To my horror I have seen ‘component’ 4×4 equipment fitters use ordinary plastic water piping in fuel tank installation. It lasts about a year before breaking up.Industrial hose suppliers sell fuel hose considerably cheaper than auto spares retailers.

Fitted to a Land Cruiser FJ-79 this Baillies Offrosd tank carries 170 litres and extends the diesel vehicle's range to a whopping 1500 kms. A similar tank is also made for the Land Cruiser 80 and 100.

Routine fuel from auxiliary tanks can be done using an electric pump or the selector valve. I prefer the selector valve option because of the notorious unreliability of fuel pumps.

carrying fuel

Never Use ordinary plastic containers to carry fuel, as they are unreliable and after time the plastic can become brittle and slightly porous, causing fuel to seep out and create a fire risk. Bumping and jolting over rough terrain stresses plasic containers carrying liquid, and the risk of breakage when filled with fuel cannot be over-stressed. Steel jerrycans are therefore advised. When purchasing Jerry cans look closely at the seal clamp. Some cheap types leak and become a never ending frustration , so spend a little more and get good ones. Ex-Army Jerrycans, if in good condition, are cheap and can be repainted. (I advise not crossing the border if they are painted military drab. Diesel is less hazardous to transport than petrol, but if you are carrying diesel in Jerrycans once used for petrol, remember that as little as 2% mix will render it as volatile as pure petrol, so empty the cans completely.

Jerrycans should be accompanied by a Jerry-spout; a pouring spout that makes decanting much easier. I suggest the rigid types for general use and a flexible type for a narrow-aperture filled of unleaded fueled vehicles.

Water tanks

Water tanks can be fitted to your vehicle by most safari vehicle supply workshops or can be installed by anyone with some DIY ability and welding skills. Water tanks must be very strong so they don’t crack under vibrations and flexing created when a vehicle moves over rough ground and corrugations. The selection of a position in which to fit a water tank will depend on your particular vehicle. The same positions recommended for fitting additional fuel tanks apply to water tanks. However, while fuel should never be carried in front of the engine because of the fire risk, water carried here aids weight distribution and is safe. however, if a large quantity of water is carried in front, it is advisable to strengthen the front springs. Tanks under the seat in Land Rovers, a position often used to fit fuel tanks, tend to get quite hot and make the water less pleasant to drink, but convenient for washing dishes. The tunnel behind the rear wheel arches in Land Rovers is an ideal position to fit a tank. For easy access, the tap can protrude out of the back of the vehicle and in this position the water can remain delightfully cool. In pickups, an obvious position is inside the loading bay as far forward as possible. Carrying water on the roof is not advised for a number of reasons. the tanks get warm, require some effort to fill if a running hose pipe is not available and severely compromise a vehicle’s center of gravity. Tanks fitted in the load bay of station-wagons can be semi-permanent with a tap fitted.

There are few things as convenient around a camp as a fixed tap on a vehicle or trailer. The tap used is a Cobra lockable garden tap.

Consideration when piping from water tanks:

Secure all exterior water taps with small Padlocks to prevent theft.
I suggest wrapping rubber bands around the locks to prevent them being damaged.
By attaching a tyre valve to the top of a tank and pumping in air, the pressure will force water out of the pipe. Beware of over-pumping or you may split the tank.