It isn't overcarbonated. I released all pressure, waited 8 hours, released it again, for 2 days after putting the keg back together. I did that until there was no pressure in the keg when I pulled on the relief valve. I have to assume the beer at that point was flat. As soon as I hooked the lines up I got foam again.
And yes when I had it apart I disassembled the locks, cleaned and sanitized the poppets and springs.