DG Fuel hose replacement - with diagram!

[StuM]

Hi All,

As the age and provenance of the fuel hoses on my van are unknown to me, I am going to do the prudent thing and replace them all. I have read the Wiki and performed various searches on here, but am still a bit unclear on diameters and type of hoses required. To assist my (and hopefully others) understanding, I drew this:



On my 1985 DG, there are the following connections around the fuel filter, is this normal?



The questions I have are:

1. How many meters of 5.5mm (internal bore) hose would be needed for the whole van?
2. Is the 'hard' pipe OEM? It is black nylon(?).
3. Would you replace the hard pipe with flexible? Would that be 5.5mm - so making it 5.5mm all the way from fuel filter to fuel pump?
4. Is the return hose to the tank from the pump 5.5mm or 7mm? Would that need a 5.5mm --> 7mm adaptor of some kind?
5. Brickwerks suggests that 790mm of 5.5mm is needed for a T25 replacement - do you think that this means all possible fuel pipes - perhaps excluding the 7mm ones?

Sorry for all the questions, I wanted to find out before ordering the wrong bits. I'm going to replace all the grommets etc as well at the same time.

Thanks in advance,
Stu

[fairwynds]

Stu
I have this job to do in the not too distant future. I have just spent a while looking up the Wiki from the top post on the tech forum ( a 'sticky' post.....) and the lengths are outlined there.
Incidently, I am also going to replace my metal fuel tank with a plastic replacement, which will be housed in a metal 'cradle'. I spoke to the MOT man yesterday and explained what I wanted to do (the fuel tank is a purpose built one from a boat!) and he said its no problem as far as MOT/regs.
Good luck with the job - I will watch the post with interest, and thanks for the diagram and pics - keep em coming!
Cheers
FW

[scottbott]

just did mine two weeks ago,bought 2metres of 5.5mm just to be safe and have quite a bit left over,bought stainless hose clamps(not jubilee) clamps,do not forget the two bits of pipe going through the bulkhead

[StuM]

Thanks both.

Scottbott - did you keep the 'hard' nylon pipes from fuel filter back?

Cheers,
Stu

[Doctor Foster]

Have done mine also but only the flexible hose not any of the hard pipe as its was in sound condition. I bought 1 metre of 5.5 and 7mm and just managed it so best to buy more than you need. What you have left over keep in your van as spare just in case

[scottbott]

left hard lines as they looked in good condition

[Oldjets]

Good diagram - would only add that on my DG there are hard lines incorporated into the expansion tank lines too. I have replace the flexible lines in the engine bay - these are 5.5mm as is the flexible from filter to feed hardline. Tank to filter is 7mm as you have marked it. The arrangement of hoses around the filter looks original, or at least, mine is the same. The flexible joining the return hard line to the tank is a special hose I think - 7mm reducing to 5.5mm. Haven't done mine yet, so not sure how to go about it, as I think it is obsolete from VW. Maybe incorporate another filter into the line as a connector?

If you have a VW van centre near you, go along and ask nicely to have a print out of the appropriate parts page from their database (better to visit on a quiet Saturday) - it details all the fuel lines with dimensions and part numbers. My local dealership was very helpful with identifying the various bits.

Oldjets

[StuM]

Thanks for that.

I considered the filter option for the 5.5mm to 7mm tank return - I'll see if I can find a reducer connector, although no doubt the size will be an issue!

Will look up my local VW Van centre.

[liliball]

Gents, not wanting to throw a spanner in but what are the consequences of using 7 or 5.5mm all around? if any.