MOT advisory: brake disc worn, pitted or scored
Brake discs are the metal plates the pads squeeze against. Over time they wear thinner, grow a lip on the outer edge, and pick up pits from rust or score lines from grit. The tester saw some of that but decided the disc wasn't seriously weakened, so the car passed with this note.
What the tester wrote
| Result | Wording on the certificate | Category |
|---|---|---|
| Advisory | Brake discs: worn, pitted or scored, but not seriously weakened | Advisory (pass) |
| Fail | Brake discs: in such a condition that it is seriously weakened | Dangerous |
What the MOT checks
Testers look at the disc surface through the wheel and judge its condition. The MOT bar is high on purpose. A disc has to be seriously weakened to fail, and being thinner than the maker's figure isn't a reason to fail it on its own.
That's why this note is common and the matching fail is rare. Light surface rust after a car has stood for a few days is normal, and it's not what this note is about.
"A brake disc or drum must be significantly worn before you should reject it. Being worn below the manufacturer’s recommended limits is not a reason in itself."
MOT inspection manual, section 1.1.14 Brake discs and drums. Read it on GOV.UK
How common it is
In 2025 this advisory was recorded on 8.9 in every 100 class 4 MOT tests (2,970,156 of 33,210,774 initial tests). The matching fail was recorded on 0.2 in every 100 (73,538 tests).
The typical car with the advisory was 11 years old with 77,975 miles recorded (medians).
| Age at test (years) | Advisory per 100 tests | Fail per 100 tests |
|---|---|---|
| 0-2 | 3.3 | not shown |
| 3 | 4.7 | not shown |
| 4-5 | 6.6 | 0.1 |
| 6-7 | 7.8 | 0.2 |
| 8-10 | 9.4 | 0.2 |
| 11-14 | 10.8 | 0.3 |
| 15-19 | 11.6 | 0.3 |
| 20+ | 9.6 | 0.2 |
'Not shown' means fewer than 1,000 tests in that cell, or a cell hidden so a small one can't be worked out. Age is years since first registration. First MOTs often happen just before a car's third birthday, so many show as age 2.
Does it turn into a fail at the next MOT?
We followed the same cars to their next MOT, 240 to 500 days later (2,470,759 pairs where this advisory was recorded). 0.9% failed on the same item at that next test, and another 30.8% had the same advisory again.
Among cars where this item wasn't noted at all, 0.16% failed on it next time. So a car with this advisory was about 6 times as likely to fail on this item as one without it, though the chance is still small.
These are averages. We can't see what owners did between tests. Some will have fixed the problem, and a fix would stop a fail.
What it usually means for a buyer
This advisory rarely turns into an MOT fail, but that doesn't mean the discs are fine. The MOT isn't a service. Worn or pitted discs can judder under braking, make noise and stop less smoothly.
Discs and pads are often replaced together, so treat this as a running cost to price in. On the test drive, brake firmly from speed. A steering wheel that shakes under braking points to discs that need replacing.
Typical fix
Discs are replaced in pairs on the same axle, usually with new pads. A garage measures the thickness against the maker's minimum, which tells you more about wear than the MOT note does. Prices vary a lot by car and garage, so get a quote for the specific car.
Questions to ask the seller
You can read any car's MOT history, including advisories, free on GOV.UK. Our MOT advisory decoder explains the other notes in plain English.
Related MOT advisories
- Brake pad wearing thin
- Rigid brake pipe corroded
- All MOT defects
- Buying a used car: a step-by-step guide
Sources and limitations
- Data: DVSA MOT anonymised test results and test items, class 4 initial tests, 2024 and 2025 (open data on GOV.UK). Same DVSA data as our MOT dataset.
- 'Fail' includes items fixed at the test centre within an hour (pass after rectification).
- An advisory is a tester's judgement on the day. Testers differ, and some problems are not visible at an MOT.
- The MOT is not a service and does not check the engine, clutch or gearbox in depth.
- Counts under 1,000 are not shown. No make or model figures are published here.
Contains public sector information licensed under the Open Government Licence v3.0. Source: Driver and Vehicle Standards Agency (DVSA), MOT Anonymised Data. Analysis by CarCheckHQ. Not endorsed by DVSA.
Written by the CarCheckHQ team.