Thread: Td5 fuel tank mods - converting to engine with lift pump

Originally Posted by workingonit

I can only speak from experience with the Tdi300 and T5 Disco. The poly tanks are tough - they can be heated to plastic state and dimpled a bit to avoid coach bolt heads if clearance is problematic. The white plastic sender units are brittle by comparison.

Regarding the Td5 sender you already have? Would it be simple enough to disconnect or remove the motor and replace it with a piece of extension tube to reach the bottom of the tank? The Td5 senders have press in fittings, and the engine has bayonet (?) so you would need to arrange a transition somewhere?

If you are thinking of adapting a Tdi300 sender unit, make sure it can be secured by the Td5 tank ring, as the rings are slightly different between models.

If you make your own (I did, out of steel) you should consider having the frame spring loaded to press against the bottom of the tank to avoid swing fatigue to the tank lid - don't simply suspend your pipes like stalagmites from the roof of the tank if there is any weight at the bottom of the pipe ie filter, pipe stiffening, float and electric resistance board. The return pipe is much shorter than the pickup.

All good points to consider....I was planning to run a VDO sender and an unfiltered pickup pipe with the return T'd somewhere low around the filler neck so I can use it as a sneaky 'siphon'. Handy if I want a bit of fuel for fire starting.

Do you have any pictures of your set up?

Originally Posted by Fubar

Do you have any pictures of your set up?

Didn't have access to a 3D plastic printer at the time - would do things differently now - may have another go!

SAM_1932.jpg

And there is this for $165 - but still fragile white plastic - the plastic moulding around the steel outlets cracks, particularly if not very careful when doing up the securing nuts. Maybe cheaper elsewhere. Note it is also spring loaded against the bottom of the tank. Vague memory that there may have been an issue trying to fit a Tdi300 sender to a Td5 tank, to do with the Td5 tank neck opening or ring fit.

Fuel Sender Unit 200TDI & 300TDI Discovery 1 (1993 on) & Range Rover for $165 - MyShopping.com.au

OK, just had a dig around in the shed and taken some measurements, done some fitting to remind me. So here's a long winded post.

The original steel Range Rover tank in the chassis was rusted out.

Trouble with doing projects in Darwin is getting second hand parts, coming in dribs and drabs and not in the time frame you need them, or from interstate by paying huge freight to get them here.

I managed to source locally a second hand Td5 tank, and separately a broken fuel pump module.

Do I get a new Td5 pump unit ABS plastic(?) $200-300 - have seen copies in the cheap white brittle plastic for $100-150 - and I don't need the pump - if I keep the pump on board but unpowered will it hinder flow? Do I remove the pump and try to extend the pick up pipe, risking breaking plastic? And I'd need to buy two of the pre-shaped special fixture pipes, make adaptations for the injector pump end, and block the other holes.

Decided to make my own, as you have seen.

Of course, when I'm just about finished, I get a Disco 1 V8 wreck cheap. The petrol tank is essentially the same as the diesel Tdi300 tank, same underbody steel carrying sling and hold down strap (same for the Td5) - there are some differences in lines out and return lines, the fuel module has a pump while the Tdi300 does not - but by comparison the Td5 holds an extra 7 litres.

If I'd have come across the Disco 1 wreck before the Td5 tank then I would have used the Disco 1 tank and bought a new fuel module.

But given I've gone so far with the Td5 tank I will stick with it, as said it holds an extra 7 litres more than the Tdi300 tank, from memory.

Well, why not stick the Tdi300 module into the Td5 tank? For starters, the Tdi300 'lid' on the fuel module is 117mm diameter compared to 126 for the Td5.

Yes, the Tdi300 module will sit in the neck of the Td5 tank, but it sits in the lowest of two stepped lips found in the rim - the Td5 unit sits in the upper lip. Even though the Td5 securing ring can cover the Tdi300 module the Td5 securing ring can't actually press home on the Tdi300 module because it sits on the lower lip. My Tdi300 module was missing a rubber sealing sleeve that sits under the lid, and which may raise the lid slightly so that the Td5 securing ring can apply pressure, but I can't guarantee that.

OK, replace the Td5 securing ring with the ring from a Tdi300 tank. From memory fitment was an issue, even if you could screw it on you still may not reach the Tdi300 sender unit on the lower step - but then I don't have the rubber sealing sleeve which could add lift and make up the difference.

The inside diameter of the Tdi300 one piece plastic securing ring is 125mm. The inner diameter of the two piece Td5 securing ring, steel outer screwed onto a brittle white plastic inner, is 127mm. Funnily enough the Td5 lid will screw onto the Tdi300 tank, but not vice versa if I remember correctly (can't do this test now because the plastic inner of the Td5 is on the tank neck and I may break the remaining lock tab if I try to remove it - already broken one of two tabs). The Tdi300 thread is ACME(?) in style (thick with squarish corner), while the Td5 thread would have been ACME except that one side has been modified from square - hard to describe.

There is a ring running around underneath the cap of each type of module - the diameters are almost identical. It is used to seat the rubber sleeve seal (that I'm missing from the Tdi300 module). The ring on the the Tdi300 is 122mm deep while the Td5 is 116mm deep. The mouth of the two types of tank have the same diameter, so either unit with correct rubber sleeve attached should fit through. As said, the rubber sleeve seal was missing from my Tdi300 module when I got it, and of course the Td5 rubber sleeve doesn't cover the full depth of the ring under the Tdi300 cap. I forced the Td5 rubber sleeve onto the Tdi300 module up to the lid, but could not get it through the tank hole because of distortion of the rubber sleeve. Anyone else fitted a complete Tdi300 fuel module to a Td5 tank?

I don't know if Defender poly tanks and their space in the chassis frame are the same as Disco/RRC so can't make a serious recommendation - but as said if I'd got the Tdi300 tank early on then I'd have used it and a new fuel module.