I get a scraping noise from the rear brakes, but the pads seem ok 6 January 2017  |  Stu

Affecting: Xantia & C5

This is an odd one but very common in the Xantia, and is reappearing in the C5's (Come on Pierre you knew this would happen!). The rear brake caliper is mounted on a rear suspension arm bracket. Due to electrolysis (nice word) between the steel of the arm and the alloy of the caliper body, a build up of white corrosion appears. This happens very slowly, but like a daisy slowly pushing it's way up through tarmac the corrosion slowly pushes the caliper away from the bracket. Eventually the caliper becomes misaligned to the brake disc, which in turn causes the top and bottom edges of each brake pad to come into contact with the disc (the grating noise). In the end the disc can be unevenly worn. Assuming you can put up with the noise that long. To remedy this effect simply remove the caliper, carefully clean up the mating surfaces and liberally apply 'copper grease' to both surfaces before refitting. This will stop the electrolysis for quite some time. Certainly till the next pad change. Be aware that, often the caliper retaining bolts need a little coaxing with a lump hammer and drift to get them to shift. Here are the correct replacement bolts:

For C5      https://www.eurocarcare.net/brake-pads-rear/ecc440550-rear-caliper-retaining-bolt.html