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Is your brake testing up to standard?

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Image of coach on a street

Brake performance testing should be a key part of your maintenance regime that needs to happen at every safety inspection.

And, if you find any braking performance problems while the vehicle or trailer is in use, you’ll need to get a measured brake efficiency test before you use the vehicle again.

For most of you, this is standard practice and shows that you’re committed to running your fleet compliantly and protecting other road users.

Tragic consequences

But unfortunately some licence holders don’t meet the minimum standards and the consequences can be devastating.

In 2015, DVSA examiners investigated a road traffic incident involving a 32-tonne tipper vehicle. Four people, including a four-year-old girl, were killed when the vehicle’s brakes failed on a steep hill.

Our investigation found the operator’s brake testing was far below the required standards. The company’s approach to brake testing was nowhere near thorough enough, and on 5 out of 13 safety inspection records, the brake test section had been left blank.

In the other records, the comments were too limited for anyone to understand what they meant.

Successful court convictions

Two individuals from the company were each convicted of four counts of manslaughter at Bristol Crown Court.

The company director was sentenced to 7 years and 6 months in prison and the mechanic was sentenced to 5 years and 3 months in prison.

The Traffic Commissioner revoked the company’s operator’s licence and both the company and its director were disqualified from holding or obtaining another operator’s licence for two years.

Even if nothing this catastrophic happens, our vehicle examiners  will still take your vehicle off the road and can issue you with a fixed penalty if they find dangerous problems with your brakes. This could lead to an investigation and referral to the Traffic Commissioner.

Following best practice

You should carry out routine safety inspections of your vehicles on a regular basis. Annex 4 of the Guide to Maintaining Roadworthiness provides tips for you to work out how often a vehicle needs to be inspected.

A braking test needs to form a part of each safety inspection. If possible, you should always brake test a vehicle or trailer laden. You should also use a calibrated roller brake tester (RBT) to measure:

●    individual brake performance

●    overall braking efficiency

You should undertake brake testing with the vehicle or trailer laden in order to get meaningful results. If this test shows the brakes aren’t working properly, then the vehicle or trailer isn’t roadworthy.

You could also use an approved and calibrated decelerometer to measure overall brake efficiency if you’re testing vehicles without trailers.

And you should always try and obtain a printout of the brake test from either the RBT or decelerometer and make sure it’s attached to the safety inspection record. If you can’t get a printout, the inspector should record the results on the safety inspection report instead.

If you can’t carry out a brake test during a safety inspection, the vehicle’s braking performance must be assessed using a road test.

This needs to be carried out under controlled and safe conditions. The safety inspection record should also say that the brake performance was assessed by a road test.

You can use an Electronic Braking Performance Monitoring System (EBPMS) to assess trailer braking performance using data collected while the vehicle is in use. You can find more  guidance about this here.

More information

Our Guide to Maintaining Roadworthiness gives more advice on brake testing and what you have to do.

You can also read our MOT heavy vehicle brake test best practice guidance to find out more.

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  1. Comment by Trevor posted on

    A major factor on brake performance is gross weight. Overloading increases the stopping distance. Prosecutions usually state that overloading is an offence but rarely spell out the possible consequences? Does awareness of the dangers need to be increased?

  2. Comment by gary posted on

    Hi there, we operate a fleet of coaches and have always carried out a decelerometer brake check every 4 weeks (28days) alog with our safety inspection. we also carry out a roller brake test on every vehicle every 6 months, voluntry before mot and then 6 months after that date. would you say that this is efficient or would we need to carry out more roller brake checks? our machine is vosa opproved and is callibrated by the manufacturer every 2 years.

    many thanks

    • Replies to gary>

      Comment by Chris (DVSA) posted on


      This sounds fine. Our advice is that if they are picking up braking issues in-between inspections then we would recommend reviewing your procedures, but if it all appears good then this is sufficient.

      The advantage a roller brake test is it measures the performance of the individual brakes - decelerometers can't do this.



  3. Comment by Trevor posted on

    At first glance it appeared digital decelerometers were no longer acceptable but further reading indicates they are?
    This is interesting as I understand all MOT test stations have calibrated decelerometers and could test all rigids? Just a case of negotiation. We bought a decelerometer a few years back for periodic inspections and it has proved worth the investment.
    Prior to that we road tested the vehicles, heated the brakes up and recorded the disc and drum temperatures to check for operation and imbalances. Infra red heat sensors are not expensive and have a multitude of uses.
    The obvious question is how drivers check their brakes as part of their daily checks? The first problem is that unless the vehicle is in constant use the brakes, drums, disks and wheels will be cold. That won't say much? Next what type of system is fitted and how should the pedal feel?
    Generally any signs of oil on drums, disks and wheels indicates a problem.
    Going many years back one check was dropping into a low gear, pulling handbrake hard on and letting the clutch out. If the vehicle moved the handbrake was suspect. If the engine stalled the handbrake wasn't bad. If the vehicle remained stationary and the engine kept running you needed a new clutch!
    Once in use it was a good habit to walk around when the brakes were hot. It is possible to feel the heat in the disks and drums without touching them. I sometimes used to tap them gently with my middle finger. The technique improves after you have left a skin imprint on a hot disk a couple of times.
    Last resort was spitting on them through the wheel holes or peeing on them (usually nightshift). This was quite conclusive and involved most senses. The more mild mannered could use a spray bottle? Water might be best?
    One of the biggest shocks in driving is moving, newly qualified onto a fully laden vehicle.
    Hopefully someone will bring an app out to test deceleration?
    Driving a fully laden vehicle requires extra concentration and forward planning. They may not brake or steer as expected? Experience really? Confidence or lack of it is transmitted through the seat of your pants. Best to carry a spare pair in the early years?
    Sorry for the epistle, but many these days don't seem sure what they are looking for?

    • Replies to Trevor>

      Comment by Chris (DVSA) posted on

      Hello Trevor,

      In answer to your decelerometer question: there is an approved list of acceptable decelerometers. They are accepted to test rigid vehicles, but we don’t recognise that they can be used to get a braking efficiency reading for trailer brakes, although some operators use them to test the vehicle and trailer combination overall efficiency. You can find more information here:

      In terms of how to check brakes as part of a daily check, the main aspects are the air system or any obvious visible problems, like the anti-slip pad on the brake pedal and park brake controls.

      Drivers should check for air leaks and see if the air gauges are showing air build-up correctly. Vehicles have various warnings and malfunction indicator lights, for air pressure, brake linings, and ABS and EBS for example. Drivers need to make sure no faults are indicated on these systems before using, or if a warning comes on, they make sure the vehicle can still be safely driven.

      During driving, professional drivers should know that the vehicle is behaving normally under braking, not pulling to one side or making strange noises, that performance appears to be normal and no warning indicators are displayed.

      I hope that answers your main questions.