GasTapper has some detail on how to access (siphon) fuel with our access line on our home page. This blog offers some additional insights on how this is done and the problems you can run into.
GasTapper learned over the years that lubricating the narrow access line and the larger outer guide tube can improve success substantially. We like to use white lithium grease. and alternative is WD-40 or similar. The grease is best asn the WD-40 tends to evaporate. This lubricant really helps reduce overall friction along the entire path helping you to overcome the actually blockage issue at the end of the tube so you can get to the gas or diesel fuel.
Reducing friction gives you the ability for greater control and options where you are hitting a rollover ball or a simple hard edge or flange (usually the biggest issue).
The hose continually lands in the same exact spot which is a simple edge or flange (sown in picture. This is at the bottom of the fuel neck and has a metal fence guard which is the source of the flange). If you can get past it, you would be in the fuel but no matter how much fishing and twisting you do, you land in the same spot, due to the nature of the fuel neck path.
How we solved it:
Recently GasTapper was trying to siphon fuel from a 2015 SRT Dodge Challenger and we hit what appeared to be a hard insurmountable stop. Our historical experience had been that this car was accessible so what changed?
We pulled out the tunnel camera and went hunting for an answer. Sure enough, we were hitting a hard edge flange where rubber and metal connected in the neck.
We solved the problem by first lubricating the GasTapper access line so we had greater maneuverability. Then I got to thinking about the hose tip and came up with a simple idea to avoid the flange. I put a bit of a bend or slight kink in the 1/4 inch fuel access line about 2 inches up from the tip or end. This causes the tip to avoid the flange when rotated just right. Bingo, we were in the fuel!