Thread: Developing HD plastic sill tanks for Defender

Originally Posted by rijidij

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

Cheers Murray, that's the kind of switch I was thinking of. The low level buzzer could be handy also.

Re the sender unit, about how much are the VDO? Trying to keep costs down as much as possible. I'm leaning towards an aftermarket defender sender which has incorporated fuel pick up. This would give the option of using the standard fuel gauge with a switch to select which tank. Or for those who like two gauges, fit another gauge.

Still considering all options, and have a few defenders, 130, 110, 90, lined up for next friday hopefully.

Originally Posted by strangy

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.

Thanks. I'll be doing number 2 for my old truck, nice and simple.

For transfer set ups it can get a bit complicated if you want to make it fool proof. With the low level pump cut off, how do you get to use all the fuel in the tank? there could still be a fair bit left when it cuts out. You could override it but then your back to human error. Be good to have a way of cutting the pump off when it starts sucking air. Simplest way I can think of is to mount the pump where you can hear it change tune so it reminds you to turn it off! This worked great in an old county we had, the transfer pump was under the floor and made a loud noise when dry.

The other thing to think about is how to stop people overfilling their main tank? even if you don't start transferring until the main is nearly empty you could still overfill it as the 130 sill tank should hold more fuel. Could rig up a high level pump cut off? overflow line back to aux tank?

Just had another idea for transfer. Have a high flow pump, set up with a hold on type switch (like a starter button) so the "passenger" has to hold the button on while watching the fuel gauge fill up. Basically like filling up at the servo, but driving. Could work!? Or because its filling up quickly a normal switch may be ok as you are watching it fill up. Or have the fancy cut out like on the servo pumps when its full, hmmmm.

I've been thinking about on board water with a tap for our 110.
I'll hold off a little while to see how your tanks come up

If you want a 110 to try things on yell out, I could come up on a weekend.
Be warned though, ours is about a worse case scenario for fitting bits to.
I struggle to fitt anything aftermarket to it with out needing to do some modifications.

Plan B would be a Defender(and others) BBQ day to get a feel for the extreme tolerances.
Supply a hot plate and it could be a BYO event, again yell if I can help.

If you have a dual filler set-up overfilling isn't an issue as it just flows back into the auxiliary tank.

Originally Posted by carlschmid2002

If you have a dual filler set-up overfilling isn't an issue as it just flows back into the auxiliary tank.

Thanks, good point, will just have to work something out for those with separate fillers. Dual filler certainly the go for 110. Cheers

Sent from my E5823 using AULRO mobile app

You don't need to work it out at all...
Make it Dual filler regardless.

Even for those with separate fillers like mine. A simple hose from the main filler neck, just below the breather to the same spot on the secondary neck will sort any concerns. A t into the main and aux breathers would work. Couple fittings and an extra 1.5m of hose worse case. I agree with others, it's not your concern unless you are going to provide installation as well.

Originally Posted by strangy

Even for those with separate fillers like mine. A simple hose from the main filler neck, just below the breather to the same spot on the secondary neck will sort any concerns. A t into the main and aux breathers would work. Couple fittings and an extra 1.5m of hose worse case. I agree with others, it's not your concern unless you are going to provide installation as well.

Thanks, just want to make sure that I have enough fittings to cover most options, got it sorted I reckon. And I will offer just the tank to those who wish to rig up themselves, but will also a complete kit.
Cheers, Andrew.