Thread: Auxiliary Fuel Tanks

Hi Weakestlink, I'm close to fitting a Boab aux tank and was wondering if you could help with a couple of questions:

1. If the aux tank gravity feeds to the main tank do you have difficulty filling up if you only have a few litres left in the main tank? I'm thinking it could take some time for the rear tank to gravity feed into the main tank.
2. Have you found a non-return valve to fit in the 32mm hose which connects both tanks? If so does it or will it restrict the flow when you are filling up both tanks, and what brand / spec non-return valve have you used.

It would be a pain as you say to find all the fuel flows back into the rear tank and potentially leving the vehicle out of fuel.

Cheers
Barry

Pleased to help with your questions Barry

1. If the aux tank gravity feeds to the main tank do you have difficulty filling up if you only have a few litres left in the main tank? I'm thinking it could take some time for the rear tank to gravity feed into the main tank.
Not found any problem at all with this. Just after fitting I had a very low main tank and put 180litres in to both with no blow back or issues in slow filling. used a HI Flow a few times- no problem noted.

2. Have you found a non-return valve to fit in the 32mm hose which connects both tanks? If so does it or will it restrict the flow when you are filling up both tanks, and what brand / spec non-return valve have you used.
Not yet but still on my to do list-

It would be a pain as you say to find all the fuel flows back into the rear tank and potentially leving the vehicle out of fuel.
Honestly I doubt it would be a problem unless really low on fuel and running up a mountain. I noticed it only on a very long very steep climb. A rule I have is to always have 1/3 remaining fuel for an emergancy, from my ofshore boating bad habits I guess. 30 litres or even less even if most drained back to the rear tank should give me more than enough left covering the fuel pick up in the main tank. I will put a one way valve in as I like to spend a lot of time on hills in in a very reclined seated possition

Cheers
James

Originally Posted by bbyer

The Ford pre 1926 Model T's had a similar concern - the engine could be starved of fuel going uphill when the under seat fuel tank level was low. The solution was go go uphill in reverse.

After 1926, the gravity feed fuel tank was moved from under the seat to in front of the firewall and higher up.

They were not much for hauling trailers in those days.

If my main drains to my AUX and the car stops i might just consider trying the reverse up the mountain trick.

Originally Posted by lrdef110

Hi Weakestlink, I'm close to fitting a Boab aux tank and was wondering if you could help with a couple of questions:

1. If the aux tank gravity feeds to the main tank do you have difficulty filling up if you only have a few litres left in the main tank? I'm thinking it could take some time for the rear tank to gravity feed into the main tank.
...
It would be a pain as you say to find all the fuel flows back into the rear tank and potentially leving the vehicle out of fuel.

Cheers
Barry

Hi Barry, quick update for you. With the low fuel light on today (about 6 litres left) I put the car nose up on a 35 degree slope near a oval here. Ran it for 30 minuters with no drop in the fuel gauge or engine issues. Bumped it slowly it up and down the slope with my nose up at all times for another 10 minutes. It looks like only some fuel can get back the AUX tank. Give play time test I might not bother with a one way valve

In the UK they have been taking out the main muffler (mainly V8 RRS) - the one that is opposite the fuel tank and is nearly as large and putting a smaller muffler elsewhere in the system. They are reporting some reasonable power increases.

However if this muffler was removed I suspect an aux tank of somewhere about 70 litres (RRS maybe more in a D3/D4) could go in. Would probably work out a tad cheaper than a rear tank and wheel carrier if a centre tank was to be made available.

Has anyone considered this possible option?

Garry

Originally Posted by ~Rich~

LR Disco 3&4 Aux Fuel Tank 80L - Dolium Pty Ltd
There you go.

Been reading this thread and like the gravity fed idea. Went to the above link that was near the start of the thread.
Is this the right one? The one in the link says it comes with a transfer pump. Is this right?

Hi denwal
If it has a transfer pump its not the gravity fed one

connock

Hi Denwol. I purchased my aux tank through Opposite Lock. I thought it was to be a Dolium tank but it actually came out of a manufacturer in WA. Not sure of the name. This may or may not be connected with Dolium. It is gravity feed and so far I am very happy with it, although the local Opposite Lock store had to use alternative hose to connect the tanks as the hose included with the kit was crap. After looking at the design and the way it gravity feeds into the main tank I am pretty sure that the fuel can not completely drain back to the aux tank. Total cost fitted was only $1,135 which is about half the cost of the Long Ranger tank which has the transfer pump, alouth the Long Ranger tank holds an extra 22 litres.
Cheers
Barry