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The Most Common Reasons HGVs Fail Their MOTs

the most common reasons hgvs fail their mots

Posted on 20th Mar, 2017 by Dominic Benabda

In the financial year of 2015-6, a total of 417,767 MoT tests of Heavy Goods Vehicles were undertaken, with some quite interesting results. Out of these tests:

417767          tested

42821            initially failed

42630            were retested

28993            passed after the issues were rectified

We’ve taken a moment to sum up the most common issues for which these vehicles failed, to help you better understand which elements need the most attention on your own HGVs. (It’s worth noting that vehicles can fail for one or more of these items, so the percentages overlap and can’t be totalled with each other.)

Common Reasons For HGV Fails

under carriage of hgv

Wiring Defects

  • In-cab faults with the wiring and electrical systems of the vehicles accounted for about 1% of all the HGV failures. The tests for these systems involve checking to make sure the electricals haven’t been physically chafed or damaged by heat, potentially rendering them dangerous.

Speedometer and Tachograph Faults

  • Roughly level with wiring and electrical systems in terms of frequency, these also accounted for about 1% of the failures. The regulations state that trucks must have a tachograph fitted unless the vehicle or operator is specifically exempt. The tachograph seals are also subject to a visual check as part of the inspection.

Suspension Issues

  • Faults with the suspension represented around 1.6% of the total failures of HGVs. In order to pass the test, the suspension must be attached correctly, fully secure and free of any defects that could impact its functionality.

Steering Mechanism Faults

  • These types of issues accounted for around 1.6% of the annual test failures. Steering mechanisms undergo standard tests to ensure that it isn’t too stiff, resistant or rough.

Concerns With Lights and Headlamps

  • One of the foremost reasons for the failures of Heavy Goods Vehicles, issues with headlamps specifically represented 4.8% of the annual test failures.
  • Meanwhile, other lamps such as fog lamps, stop lamps, side marker lamps, rear registration lamps all accounted for 3.8% of annual test failures. They are subject to tests ensuring that they’re not missing or insecure, are displaying the correct colour, are correctly positioned and sufficiently bright.

Failures With Braking Systems

Problems with various braking systems also accounted for a sizeable number of failures in HGV tests for that financial year. They include:

Parking And Secondary Brakes

  • 1.2% of HGV fails were caused by an issue with the parking brake, while 1.4% of fails were associated with the secondary brake.

Service Brakes

  • Service brake performance was another problem faced by hundreds of HGVs, responsible for 2.5% of failures.

Brake Systems And Components

 hgv brakes

  • A large proportion of failures were to do with brake systems and components, as many were found to be damaged or not functioning correctly. They were responsible for 3.3% of fails.

Our own VT Brakesafe system is designed specifically to deal with some of the problems surrounding the use of parking brakes. It’s a failsafe that automatically applies the handbrake if the drivers forgets, at the same time sounding an audible warning that doesn’t stop until the driver manually adjusts it. This is designed to deal with the dangers of ‘runaway vehicles’, caused by HGVs slipping down inclines. Our VT Stopsafe system, meanwhile, gives the crew means to apply the brakes in a controlled manner should the driver become ill or injured at the wheel, allowing them to bring the HGV to a safe, controlled stop.

Feel free to browse our case studies to find out how we’ve already helped organisations just like yours drastically improve the safety of their heaviest vehicles. If you need any help or advice, or have any questions you need answering, we’re only too happy to help – you can reach us on 01254 679 717.

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