I would definetely take it all apart, clean it and lubricate. Also would give you an opportunity to check for any wear and damage. I’m sure somebody will come along showing the schematic, or point to a thread where it was discussed.I've noticed the mechanism that holds the panniers onto the frame (not the key lock) has been getting more and more difficult to engage each season. I have to put a lot of force into pushing down the handle. To the point where I'm worried I'm going to break it or the little arm that comes out to press against the frame, since many of the parts are just plastic.
All the contact parts are properly aligned and there's nothing in the way.
Do these things need lubrication over time? If so, where exactly? Can it be disassembled for inspection and cleaning?
