Those black hoses I do not think are PTFE as they do not feel like it (not as slippery) if those are the ones you mean then those black hoses slip into the top black plastic piece that is on top of the motors. It just goes in a little bit and they do not go in the extruder at all. The black plastic piece with the two long 3mm screws in the top and the filament hobbed section is below that clunky black piece and it is that piece those hoses go into. Your motors had the black plastic piece on top of them both (it is one piece) right?