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MOT defects · Brakes

Brake effort fluctuating MOT advisory: what it means and which cars get it

In DVSA MOT data for 2023, analysed by RegTail, testers recorded this as an advisory on at least 0.08 in 100 and as a failure on at least 0.01 in 100 initial MOT tests. The Hyundai Getz got it most often: recorded 2.5 times per 100 of its 23,077 tests.

DVSA wording: Excessive fluctuation in brake effort through each wheel revolution.

Failures
0.01 in 100
At least 1,894 tests in 2023
Advisories
0.08 in 100
At least 25,556 tests in 2023
Most often
Hyundai Getz
2.5 per 100 tests

What it means

The braking force on one wheel rises and falls as it turns. That usually means a warped or unevenly worn disc, or an oval drum.

How serious it is

A major defect, so a fail, when excessive. In 2023 it was mostly recorded as an advisory.

Source: MOT inspection manual for cars and light vans, section 1.2.1.

  1. Major Fail
    It may affect the vehicle's safety, put other road users at risk or have an impact on the environment. Repair it immediately.
  2. Advisory Pass
    It could become more serious in the future. Monitor and repair it if necessary.

What fixing it usually involves

Usually new discs or drums, with new pads or shoes.

A general guide, not a quote: ask a garage to inspect the car.

Which models get it most

Per 100 initial MOT tests on each model, among the 49 models with at least 20,000 tests where it is among the 40 most common items. DVSA MOT data for 2023, analysed by RegTail.

ModelTestsFailAdvisory
Hyundai Getz23,077·
2.5
Nissan NV20026,275·
1.9
Volvo C3024,617·
1.7
SEAT Arona39,192
0.8
0.8
Toyota Hilux72,537·
1.4
Hyundai i4022,400·
1.3
Mazda 667,869·
1.2
Vauxhall Crossland51,812
0.4
0.7
Jaguar XF102,260·
1.0
Alfa Romeo Giulietta26,655·
0.9

What to check at a viewing

  1. On the car
    Brake firmly from about 40mph on the test drive: a pulsing pedal or a shaking steering wheel is the symptom.
  2. In the MOT history
    If this appears as an advisory, see whether it came back at the next test or turned into a failure, and ask the seller for the receipt if it was fixed.

Check a specific car

Fleet averages only go so far. Enter the registration to see that car's own MOT history, mileage record and current condition, free.

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Questions

What does "Brake effort fluctuating" mean on an MOT?
The braking force on one wheel rises and falls as it turns. That usually means a warped or unevenly worn disc, or an oval drum.
Brake effort fluctuating: is it an MOT fail?
A major defect, so a fail, when excessive. In 2023 it was mostly recorded as an advisory.
Which cars are most likely to get "brake effort fluctuating" on an MOT?
In DVSA MOT data for 2023, analysed by RegTail, the models that got it most often were the Hyundai Getz (2.5 per 100 tests), the Nissan NV200 (1.9 per 100 tests), the Volvo C30 (1.7 per 100 tests).

More brakes defects

See every MOT defect we explain or MOT pass rates by model.

Brake disc worn, pitted or scoredBrake disc significantly wornBrake pads worn thinBrake pipe corrodedBrake hose ferrule corrodedBrake hose damaged or perishedBinding brakeBrake effort fluctuatingHandbrake efficiency too lowHandbrake not working on one side

How these figures are made. We counted the defects recorded at every initial MOT test (not retests) of cars and light vans in Great Britain in 2023 in the DVSA anonymised MOT dataset, 33,842,940 tests in all. Each item counts once per test. A failure is a major or dangerous defect, including one fixed during the test. A model's rate is the share of its tests where the item was recorded.

For each model we keep its 40 most frequent items, so a model where a defect is rarer than that is not listed, and figures for all cars are a floor. Defect names and explanations are ours, checked against the MOT inspection manual; DVSA's own wording is shown under each name.

Contains public sector information licensed under the Open Government Licence v3.0. RegTail's analysis of the DVSA anonymised MOT dataset, 2023 tests.