From your picture of the underside of the tank, it looks like the two protruding tags, that were in the slots you can see , have been broken off. So, your newly made tool is useless. Your best bet now is to buy an inline high pressure connector and cut the fuel pipe. Drain the tank first and with another pair of hands to hold the tank so you can cut the pipe cleanly , be careful where you cut it . You only get one chance at this.I 3D printed the "special tool" that was missing for my bike. I used Engenia's drawings, and ended up with this (I can attach the STL file in another thread somewhere if people want):
View attachment 39082
It's a nice snug fit, but I don't see how it is meant to release the end of the hose?
Here is what the underside of the tank looks like:
View attachment 39083
The centre sleeve of the attachment has 2 slots on each side where the inner joint can be seen, I assume this is where one is meant to release the connection. I just don't see how the tool is meant to help, unless something is different with my connector.
FYI, this is a 2012 TreK Amazonas.
What do I need to do to get this off?