I have Shimano 105 Dual Pivot brakes on my bike. They are pretty old (~7 years), and, although I ride the bike very regularly, I do not use the rear brake much and it has become stiff. (By stiff, I mean that the brake does not fully spring back open when I release the lever.)
Previously when this happened, I took the brake off, cleaned it, and then oiled and adjusted the pivots. I used bike chain oil (wet lube). This worked well, but the brake went stiff again pretty quickly so I'm reluctant to do it again.
Does anyone have any tips for a long lasting repair? Should I be using bike oil? Is it worth fully dismantling them (is this possible/advisable?).