I am changing out the soft fuel lines near the tank with biodiesel compatible ones (5/16" SAE 30R9 - viton lined). There are 3 lines back there... 1) Fuel Delivery (attached to fitting that is then screwed into the tank screen), then there are two lines next to each other 2) Return Line and 3) Vent line. What is odd is that the hard lines for #3 seem to require a slightly larger inner diameter (ID) line than the 5/16" I purchased. I am really struggling to push the soft line on and have gotten it slightly deeper then the clamp itself but not as much as it should be.

So my 4 solutions so far are:

1) Don't be a wussy, push that line on harder (I used some silicon spray to achieve what I already did)

2) Don't worry about it, its just a vent line, what you did is adequate.

3) Put the old soft tubing back on as it is just a vent line and the biodiesel (b100) will not really come in contact with this line anyway.

4) Buy some bigger hose.

5) Some other solution/explanation I have not worked out yet.

Thanks
Doug