Have an mot coming up and notice this orange stuff on all 4 brake disc. What is it and will it fail an Mot? What’s required to repairs it?

Thanksenter image description hereenter image description here

  • 3
    "What is this orange stuff?" ... Rust? Aug 28, 2021 at 17:49
  • 1
    If you drive it for a little bit with some decent braking, it should all be gone. Aug 28, 2021 at 17:50
  • How long has it been since you drove it?
    – GdD
    Aug 28, 2021 at 17:54
  • Such superficial rust can appear very quickly on a rotor, if not driven. Aug 28, 2021 at 18:24
  • Superficial ruse appears on any steel and cast iron that is bare , very quickly. Aug 28, 2021 at 19:18

1 Answer 1


That is, as has been noted in the comments, surface rust forming on the bare metal of your brake rotor. Generally this forms quickly, even in a few hours after parking the car depending on the conditions.

In most cases it's not a problem as it will get wiped off by your brake pads the next time you apply them.

In your case, however, it appears to have gone far beyond a normal case. If this vehicle has been parked for a while, say a few weeks to a few months or longer, then the rust can get so bad that it doesn't wipe off but rather acts as an abrasive and literally sands your brake pads to nothing in a very short period of time.

While it's a bit hard to tell from your photos, if the vehicle has been parked a long time then you'll likely need to have the brakes serviced.

  • By brake service is it a cheap and cheerful clean of the discs or do you mean the discs will need to be replaced? Thanks Sep 16, 2021 at 0:00

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .