Fuel line options? 5/16" HP fuel line work?

We have an 03 ALH jetta and it has been getting air in the system. I think its coming from between the filter and the clear line as when i touch the line with the car running it can see a bunch of bubbles through the line. I have some 5/16" HP fuel line from my other gas projects, but am not sure if they are 'diesel rated'? I also would like to incorporate some sort of sighting tube, as it was pretty useful to detect this problem, any ideas?

It will work fine

so your standard 5/16 high pressure fuel line will hold up fine with diesel? thats good to know how about something so we could see any air bubbles or the like?

my 0.02- I wouldn't use rubber fuel line unless you can verify for sure that it is rated for diesel use. Ever seen rubber that wasn't treated for diesel, and has been exposed to diesel fuel ? Over time, it turns into a gooey mess. I suppose you could cut a small sample and immerse it in some diesel fuel, but I don't know how long you'd have to let it sit before concluding it was good / bad.

My thoughts, exactly. I would look for something that said "Viton" or "PTFE," as I don't believe rubber holds up in contact with diesel.

I believe fuel rated hose is specified for gas or diesel. Bio-diesel may require a different spec hose.

Most fuel line is clearly labeled. Obviously, check first.

I believe fuel rated hose is specified for gas or diesel. Bio-diesel may require a different spec hose.

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I had past experience with fuel line bought from Summit Racing Equipment that was rated for gasoline, but not diesel. I ended up buying a full spool of Goodyear hose that was rated for diesel (because it was all I could find).

The risk is so high, because if the insides of the rubber line go "gooey", it won't be obvious from the outside, and the "gooey" goes into the injection pump & injectors.