Before I soaked mine, I take a die grinder with a wire wheel to remove the rust from the cylinder walls. Then blow it out with air to get as much of the junk out as possible. Then soak the pistons/cylinders down. That way the pistons will have less interference and resistance when taking them out.
Then if I pound the piston down some more, I clean it with the wire wheel again. Then I pound them up and out.
I like KROIL.
