Additional Fuel Tank

VW LT35 I wish to add a small fuel tank tot his madel (deisel).

The existing tank has a flow and return line, so that excess pumped fuel is returned to the tank.

Can someone advise what peroportion of pumped fuel is returned?

I wish to ann a 7 litre tank - but for simplicity to connect only a flow pipe - excedd fuel being returned to the existing tank.

I need to consider the situationwhen the main tank is full - if any a small amount of fure is returned - this will not be a problem considering the size of the additional tank.

Also, can anyone advise on taps/shutoff valave for use on a fuel line, so that I may select which one is "open"?

Thaks

Eric

Reply to
Eric
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VW LT35 I wish to add a small fuel tank to this madel (deisel).

The existing tank has a flow and return line, so that excess pumped fuel is returned to the tank.

Can someone advise what proportion of pumped fuel is returned?

I wish to add a 7 litre tank - but for simplicity to connect only a flow pipe - excedss fuel being returned to the existing tank.

I need to consider the situation when the main tank is full - if a small amount of fuel is returned, this will not be a problem considering the size of the additional tank.

Also, can anyone advise on taps/shutoff valave for use on a fuel line, so that I may select which one is "open"?

Thaks

Eric

Reply to
Eric

It won't work, the extra tank will rapidly empty itself to the big tank via the return (which is very quick). If you want an extra tank as a reserve then it really is easiest to just carry a can. If you wnat one to run a heater, then again just have an extra can or tank. If you want to increase overall capacity then add a linked tank, but bear in mind you can then have problems if you park on a hill with low fuel and the extra tank lower than the main tank. If you are determined to do it then you need to add t pieces into the system and have a tap on every line (my land rover had three tanks, all with flow/return and a heap of taps.)

Reply to
Mrcheerful

Very variable depending on engine speed and throttle setting, eg downhill coasting a lot is returned, uphill with hard throttle a lot less

Not a good idea

Landrovers, particularly older ones have a twin tank system with a change over valve, you might find one from a scrap yard, dealer?

Reply to
Cerumen

I've certainly come across ex-MOD petrol ones, not sure I've seen any diesel ones with twin tanks though.

Reply to
Willy Eckerslyke

I had one that had been converted but so long ago I can't remember the details of the plumbing.

Reply to
Cerumen

Can;t think why you want to add just 7 litres,

on my iveco motorhome i added a second diesel tank, giving me 140 litres fuel capacity, and a couple of change over fuel solenoids sort out switching between the tanks, but it was very easy to add the second tank to my icveco, i used another iveco tank mounted next to the origional one, as this vehicle used truck stle chassis rail mounted tanks.

The LT has a squat tank slung between the chassis rails at the back, you can get a long range fuel tank for the LT, it's just deeper than the stock one, not sure of the capacity, but it'd cost well over a hundered quid to fill it.. mind the normal LT's 70 litre tank dosent cost far off that to fill nowadays.

As others have said, theres a hell of a lot of flow on the return when the engine isnt running fast, i ran some fuel injector cleaner through my lt's engine years ago, it was the type you disconnect the fuel lines and run the engine off this stuff, destructions said to plonk both feed and return lines into the bottle, but i thought i was being clever by just using the feed line, took about 2 minutes to empty the half a litre of cleaner, about 90% of it had been dumped into the fuel tank via the return line.

So to plumb in a second fuel tank you'll need a couple of diesel resistant 3 way valves, manual ones prolly cost a tenner each, i used solenoid valves for my iveco tank change over, there's a bloke on ebay who sells them, (search for 3 way fuel change over solenoid) cost me about 30 quid each when i got mine, need 2 of them of course.. one for flow other for return, but that's a bit overkill just to plumb in a 7 litre tank, i used to carry a 10 litre plastic diesel can with my in my LT, made up a bracket to hold it underneath the van next to the main tank, not taking up room inside the van, and easy enough to get to if needed.

Reply to
Gazz

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Reply to
Homer

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