Ford Focus - Brake disc corrosion holes - lindisfarne

My brother-in-law has just had new brake discs fitted to his 2008 Ford Focus. The old ones had large deep pits in them. Was this corrosion or a manufacturing fault? Thanks

(I'd post a picture but that doesn't seem possible)

Edited by lindisfarne on 23/12/2014 at 23:22

Ford Focus - Brake disc corrosion holes - RobJP

You can post a picture on a site like tinypic.com, and share the link here.

It's entirely possible for brake discs to get large holes, it has a variety of causes, from low mileage (rust never gets 'scrubbed off during use), to extremely gentle use (same), to the area that he lives in (sea air = more likely to rust).

Ford Focus - Brake disc corrosion holes - skidpan

Is the car regularly serviced? A good garage would hopefully pick up this kind of issue way before it turned into large holes and recommend replacements.

Ford Focus - Brake disc corrosion holes - focussed

I have seen extensive corrosion on "stainless" motorcycle discs using sintered metal pads, put away wet after riding on salt-laden roads. The cause is dissimilar metals with an electrolyte, the salt solution, I don't know if car pads contain some metal, possible cause of big holes in cast iron discs?