Thread: Developing HD plastic sill tanks for Defender

Given the fuel out is going to be at the bottom of the tank is a drain required......pull the hose off the fuel out barb and it drains....one less hole/fitting in the tank.

Given the capacity of the tank is smaller than the main tank is there a need for a gauge? I'm figuring the tank will be either full or empty. One less hole, wiring etc

Looking forward to the end product.

^^ x2
I've been operating like this for decades now, without a problem.

Hi Andrew,
The only senders I've fitted to tanks is the VDO which is easy to fit and easy to adjust for different depths.

I like to have separate senders and gauges for each tank so I know exactly what fuel I have left. It would be good to have the option of fitting a sender, otherwise a blanking plate could be fitted if not required.

Cheers, Murray

Originally Posted by weeds

Given the fuel out is going to be at the bottom of the tank is a drain required......pull the hose off the fuel out barb and it drains....one less hole/fitting in the tank.

Given the capacity of the tank is smaller than the main tank is there a need for a gauge? I'm figuring the tank will be either full or empty. One less hole, wiring etc

Looking forward to the end product.

Thanks for the input. I reckon most people will want a gauge, was thinking the simple switch with LED's to indicate fuel level would be a good option, need a switch anyway. Just need to find them, I think LRA or longranger use them.

Sent from my E5823 using AULRO mobile app

You can get a gauge with a transfer pump switch and it has a warning buzzer when low so you don't leave the pump running. More details

Cheers, Murray

Originally Posted by Shingleback

Have ordered the ally to start making the mold, finalising the design. I have another test fit tomorrow. Thanks to Steve for the first test fit on his 130. For those familiar with the steel sill tanks, what fittings do they have? I'm planning on a large fill, probably three breathers, fuel out, fuel return, drain plug, fuel level sender. With the plastic I'll be using threaded brass inserts for the fittings. Do all breathers end up at the filler or do some vent elsewhere? And any ideas on fuel level senders, gauges, switches etc be great. Cheers, Andrew.

Most of the senders have a std/ISO type PCD.
VDO website is very helpful. Let the customer choose what resistance range they want to use.
I like the tube type senders personally for this kind of thing.
My aux tank has a VDO tube type sender with 0-90 ohm range. The sole reason for this resistance range is because of the Apexi all in one led gauge and transfer pump switch. About the size of a 10c piece.
However Apexi make these exclusively for LRA, although other lpg type offerings are off the shelf.
For simple transfer tank.:
IMO to provide level and transfer information that doesn't look/appear cheap.

1/ A tube type sender fit a factory range sender ( 320ohm irc) with low level warning to operate relay cutoff for transfer pump and simple switch with a factory gauge.
This is the easiest for any model and for later trucks like TD5 where drawing fuel direct from the aux is generally unfeasable.

For older trucks who want to draw from the aux rather than transfer.
2/ fit a factory range sender, solenoid valve switched with original gauge. An indicator light in the switch for aux/main.

And my breathers all end up at the filler neck😀

The second tank in my V8 doesn't use a transfer pump and it is one of the best setups I have seen. On the outlet line for each tank there is a solinoid tap that switches via a dip switch on the dash. It uses the same fuel pump and filter after that point (although there are two extra filters in the lines before the switch).

The advantage of this is that is say you get a hole in your main tank, you are not relying on it to transfer fuel into and you have a complete independent tank.

I have separate gauges for the two tanks which I think is a must