Rbt: inoperative on one side
This one item accounted for 0% of every MOT test carried out in Great Britain, and it is among the commonest faults on 27 different model-and-year combinations. Here is where it clusters, and what it looks like on a car you are standing in front of.
How to spot it before you buy
On a clear, safe road brake firmly once from ~30 mph — feel for pulling or judder
Pulling to one side or a pulsing pedal means warped discs, a sticking caliper or uneven brakes (£150–500+).
The models it hits hardest
Ranked by how often the fault came up as a share of that model's own tests, not by raw count — a fault in 8% of a small model's tests says more about that model than one in 3% of the Fiesta's. A linked row has a page of its own.
| Model | Years | Share of its tests |
|---|---|---|
| Hyundai I800 | 2010–2013 | 5.2% |
| Hyundai IX20 | 2010–2013 | 4.3% |
| Hyundai I30 | 2010–2013 | 3.5% |
| Kia Picanto | 2010–2013 | 3.1% |
| Nissan X-Trail | 2010–2013 | 3% |
| Hyundai Veloster | 2010–2013 | 2.9% |
| Ssangyong Korando | 2014–2017 | 2.6% |
| Mercedes-Benz Vito | 2010–2013 | 2.5% |
| Hyundai I30 | 2014–2017 | 2.4% |
| Renault Wind | 2010–2013 | 2.4% |
| Kia Picanto | 2014–2017 | 2.2% |
| Kia Sportage | 2010–2013 | 2.2% |
| Volkswagen Amarok | 2010–2013 | 2.1% |
| Renault Master | 2010–2013 | 2% |
| Ford Mustang | 2014–2017 | 1.8% |
| Hyundai IX20 | 2014–2017 | 1.7% |
| Hyundai IX35 | 2014–2017 | 1.6% |
| Nissan Leaf | 2014–2017 | 1.6% |
| Volkswagen Amarok | 2014–2017 | 1.4% |
| Mercedes-Benz X | 2018–2021 | 1.2% |
Showing the worst 20 of 27 affected model-and-year combinations. The full dataset is downloadable below.
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See whether the car you're looking at has this on record
Type the registration and you get that car's own MOT history — every advisory and every failure, including whether this one has already come up.
Source: DVSA anonymised MOT tests and results, 2023. Class 4 standard tests only. Contains public sector information licensed under the Open Government Licence v3.0.