I've got the Tough Dual Hotend, and I was hoping to use the 2-into-1 mixing block.
I didn't see any instructions anywhere on the TH3D website, so I just followed the E3D instructions for their Cyclops. After assembling everything, the instructions say to heat the hotend to 285, and then tighten both the heatbreaks and the grub screws on the sides.
I did that, but I'm getting massive leakage out of both the grub screws and the heatbreaks. Is there anything else I'm supposed to be doing? The heatbreaks got probably another 1/2 turn into the heat block and then stopped-- I can't turn them any further. Likewise, The grub screws are in as far as they'll go.