On Monday, 8 May 2017 11:04:25 UTC+1, Dave Plowman (News) wrote:
In article ,
Michael Chare wrote:
My problem has been rust on the surface of the discs leading to
potential MOT failure. It is hard to know just how much rust will be
tolerated. The difficulty I had replacing replacing pads and discs was
getting the piston to retract. I had to buy a special tool on ebay.

Any rust will soon disappear with use. Rust on the disc where the pads
don't touch doesn't matter.

+1