Man oh man are these ever a pain in the neck. They are often the worst part of doing a radiator job on one of these. Even if you have the special tool to release them half the time it doesn't work either. They are truly quick connect fitting and not quick disconnect. In this video I illustrate how to pick the retainer out of the fitting as a last resort when you are in the middle of a radiator job and cant wait 3 days the special tool in the mail. Hope this helps