James Wilby Group

Fleet Services

Brake Performance Insight

Practical guidance for operators using roller brake testing evidence to support maintenance planning, PMI checks, MOT readiness, and safer fleet decisions.

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HGV wheels on a roller brake tester

Operator focus

What stronger brake evidence should support

  • Clearer proof that brake performance has been assessed as part of the safety inspection regime.
  • Better visibility of developing issues before they become annual test, roadside, or maintenance failures.
  • More useful conversations between transport managers, workshops, drivers, and compliance leads.

Planning For Laden Brake Tests

  • Where EBPMS is not used, DVSA guidance expects a minimum of four laden brake tests spread evenly across the year, including the annual test.
  • Operators should aim for each axle to be loaded to at least 65% of its design axle weight so brake performance can be assessed meaningfully.
  • A properly timed laden roller brake test can support the safety inspection record and give workshops better evidence for maintenance decisions.

Reading The Results

  • Brake test reports help identify bind, imbalance, ovality, time lag, maximum force, and brake efficiency results by axle.
  • Imbalance over 30%, bind over 4%, ovality of 70% or higher, or maximum force below 5% can indicate a failed check.
  • Even a pass may need investigation if the vehicle was not sufficiently loaded or if performance trends are moving in the wrong direction.

When Loading Is Difficult

  • Some vehicle designs or operating conditions may make loading difficult, but this should be documented and risk assessed.
  • Alternative assessments need competent review and suitable supporting evidence, especially where unladen checks are used.
  • Physical laden testing is still expected at MOT, so operators should plan loading and evidence ahead of time.

Official guidance

This page is a practical summary. Operators should always check the latest DVSA guidance and retain suitable inspection, testing, EBPMS, and risk assessment evidence for their own fleet.

DVSA guide to maintaining roadworthinessUnderstanding your HGV or trailer brake test reportHeavy vehicle brake test best practice