fuel breather pipe specification

[getunder]

There is a wide bore breather pipe on the top front of the petrol tank. This had sagged then gone rock hard and shrunk a lot possibly being the cause of one of the two nylon 3 way adaptors that it joins to crack off with concommitant fuel fumes and spillage of fuel onto the forecourt when filling over half full.It appears water pipe may have been used in error previously. The diameter is about the same internal as garden water hose, not a size stocked by my local accessory shop as fuel pipe. What is the correct specification material for this pipe and where can I get it ?

[jaylo264]

i don`t know the spec, but i recently did all my fuel system and didn`t need to replace the top /cross breather pipes at all, they are thin walled , fairly hard plastic , don`t bend much , not at all like water pipe .
jaylo

[getunder]

jaylo, I did mine about 5 years ago and used translucent flexible pipe I " borrowed" from my works laboratory where it was used for water. Serves me right. I replaced what I am sure was garden hose which had similarly deteriorated. Was yours a piece of pipe similar to the breather pipe that runs up to the filler cap area ? sounds like it. Even so, locating some is the problem.

[BOXY]

Don't be tempted to use a plastic / PVC pipe. Over time the petrol will leach out the elastomers that make pipe flexible and turn it brittle and solid. Have you got any hydraulic hose suppliers near by? Ideally you want a fuel rated hose, ISO 7840 is a marine fuel spec, but any textile braided hose with a nitrile or NBR liner would do as a breather. I guess the size is either 16mm (5/8") or 19mm (3/4"). If you can't find any locally PM me and I'll see if I can find some for you.

[bigherb]

Have you tried VW for the correct part, was available a year or two ago.

[getunder]

Thanks guys. In the end got some wide bore fuel pipe locally from Merlin Motors, Castle combe Racing Circuit. They also do Mail Order. They supply bits for racing cars so their stuff is good quality. They are useful for odd bits that you might not find elsewhere. Have a day there, voted prettiest village in the UK and watch the races as well.

[jaylo264]

Yes , getunder , just the same stuff as goes up to near the filler cap , hope it`s not just the degraded plastic that boxy mentions !
Seems to be pukka , tho -- had a vw printing on it , wish now i`d recorded it .
jaylo

[BOXY]

If you had genuine VW tube it was probably a nylon or a fuel resistant thermoplastic material, so you should be ok.