Replacing fuel lines in 1.8t conversion - some questions

Hi all,

So I need to replace my fuel lines on my 3 door tintop 1.8t conversion. Just got a few questions Currently the car has the in-tank pump and then an in-line auxilliary pump too with a check valve just before the in-line pump.

- What's the i.d. for the fuel lines normally on a mk1? I think thw fuel lines on the S3 whre the engine comes from are 8mm i.d. so I'm hoping it's the same all the way
- When changing the fuel lines, do I need to depressurize the system somehow before whipping fuel lines off? If so, how do I do this?
- Might be a stupid question, but currently there isn't a fuel filter…should I fit an S3 one? If so I think I need funny connectors too for that…

Thanks!

7mm i/d is oem, but 8mm will do fine.

To depressurise I pull the fuel relay while it is running, that gets most of it out then just leave it for as long as possible. then put a rag over the 1st line you disconnect just in case

any injection type inline fuel filter will do, a mk2 digifant/mk3 uses normal push fittings which will do you fine if you want oem, and the mk3 has a nice filter carrier you could possibly use

you, sir, are a gentleman and a scholar

If you are running a low pressure pump as in the later EFI Golfs and Cabriolets (there are 2) one in-tank and one external,, they run at 45 psi, which the fuel lines have no "Banjo" fittings.

The earlier Cabriolets and Golfs (pre-90) with CIS have 1 or 2 pumps but higher pressures as in 75 PSI and all pressured fitting are "banjo" type with Sealing washers.

So be careful and if you would of stated your working pressure of the Turbo or Injection system type we can more accurately determine which fittings you may need and if a barbed low pressure fitting would work. Or that you needed Higher pressure fittings.

1.8T engines operate at 3 bar mostly, sometimes at 4 bar. so push fit is fine

Running standard 3 bar pressure for 1.8t engine. Currently it's all put together with standard hose and jubilee clips, it's just there are too many joins and a kink in one of the pipes, so I'm replacing it all.

The in-tank pump seems original, the in-line pump is a walbro