I am replacing the fuel sending unit in my 67 and noticed when removing the filler neck hose, there was a wire coil spring of some kind in there. It extends all the way into the tank. Kind of like the one in the lower radiator hose. What is it's purpose and how does it install? How far up the filler neck assembly does it go. Just in the hose or does it extend up into the metal tube?
The service manual and assembly manuals don't show anything about it.
Thanks,
Rich

I pulled one out of my '72 Nova's filler neck. I believe it is an anti-siphon device... I don't think they are factory and I haven't noticed any issues without it. My '69 ragtop doesn't have one and I didn't have one in my '69 coupe back in the 70's.

I believe it is an anti-siphon device....Big aftermarket seller in the middle '70's when gas prices rose from 30-40 cts. to 60-80 cts. per gal.

Big aftermarket seller in the middle '70's when gas prices rose from 30-40 cts. to 60-80 cts. per gal.

...what he said, ...they were used a lot when gas was 'expensive', ...not like today ...

Thanks for the quick response's. I didn't think about that but now that you mention it, the coil radius does get smaller and smaller until it terminates at the end. That would indeed stop a siphon hose from going very far into the tank.
It is a pain to work with so I will leave it out.
Thanks