Many thanks to Alex for replying to my query!! I really appreciate the effort you put into locating a solution to my problem, however, it hasn’t solved it yet. In one of the pictures accompanying the article, it shows two slide pins (both of which are threaded at one end). My problem is that on one of my pins there is an o-ring at the end. My concern is whether this belongs at the upper or lower part of the caliper or whether it makes no difference.