I have recently purchased a ekwb water loop and started to assemble it and came to a standstill with the Ek-acf fittings. They are basic compression fittings and I have a total of 8 of them, with 5 of them stuck. They came in the package already assembled and I can not take 5 of 8 of them apart. The three that did come apart I just screwed them into the blocks and unscrewed the black ring, but for the ones that are stuck they seem to not want to separate from the inside.