What Are the Most Common Brake Failures During an MOT in the UK

Braking defects are one of the most common reasons vehicles fail an MOT in the UK. With over 30 million MOT tests carried out annually, braking performance remains a critical safety focus under the inspection standards set by the Driver and Vehicle Standards Agency (DVSA).

If you’re a garage preparing vehicles for testing, or a factor supporting workshop customers, understanding where failures typically occur can help reduce retests and protect margins.

Below are the most frequent brake-related MOT failures seen across UK workshops.

1. Worn Brake Pads Below Legal Limit

Brake pads are one of the highest-failure components during MOT inspections.

Common issues:

• Friction material worn excessively thin

• Uneven wear across an axle

• Pads contaminated with oil or grease

If friction material is worn close to the backing plate, the vehicle will fail. Even if it passes, an advisory is highly likely.

2. Brake Discs Excessively Worn, Scored or Pitted

Discs are assessed for:

• Excessive scoring or grooving

• Heavy corrosion on braking surface

• Lipping beyond safe limits

• Cracks or structural damage

Surface rust after standing is common, especially in colder months. However, deep pitting or significant wear will result in a failure.

Winter driving conditions and road salt accelerate disc corrosion, making early spring a peak period for related failures.

3. Imbalanced Braking Across an Axle

During the roller brake test, testers measure braking force on each wheel.

Failures often occur due to:

• Seized calipers

• Sticking sliders

• Contaminated pads

• Uneven disc condition

Even if components appear serviceable visually, imbalance can trigger a failure.

Why this matters: Brake imbalance can significantly affect stopping stability, particularly under emergency braking.

4. Brake Fluid Issues

Brake fluid is checked for:

• Low fluid level

• Visible contamination

• Leaks in the hydraulic system

Fluid leaks are an immediate fail. Low fluid levels may indicate worn pads or a hydraulic issue.

Moisture absorption over time reduces braking efficiency, which is why regular fluid checks are essential ahead of MOT season.

5. Perished or Damaged Brake Hoses

Flexible brake hoses are inspected for:

• Cracking or perishing

• Bulging under pressure

• Leaks

Age-related deterioration is common on older vehicles, particularly those exposed to harsh weather conditions.

6. Handbrake Performance Below Standard

The parking brake must hold the vehicle securely.

Common causes of failure:

• Stretched cables

• Seized mechanisms

• Rear caliper issues

• Internal drum handbrake wear

Reduced efficiency or imbalance between sides can result in failure.

Why Brake Failures Increase at Certain Times of Year

March and April often see increased brake advisories and failures due to:

• Winter corrosion

• Increased mileage over colder months

• Vehicles preparing for MOT before the new registration period demand spike

For workshops, proactive brake inspections before the test can reduce retests, improve customer trust and protect workshop time.

How Garages Can Reduce Brake-Related MOT Failures

• Conduct full brake checks before submitting for MOT

• Replace pads and discs in axle sets where required

• Inspect sliders and caliper movement, not just friction material

• Check brake fluid condition, not just level

• Inspect hoses on older vehicles thoroughly

Reliable component supply also plays a role in maintaining consistency and avoiding repeat work.

Supporting Consistent Brake Performance

As braking systems continue to evolve and vehicle weights increase, consistent friction performance and material quality remain critical for MOT compliance.

For factors and garages alike, ensuring access to dependable braking components helps reduce unexpected failures and protect customer confidence during peak MOT periods.