Every year, thousands of vehicles fail their MOT test for issues that could have been prevented. Understanding the most common MOT failures helps drivers prepare properly, avoid unexpected repair costs, and improve their chances of passing first time.
Many MOT failures relate to basic wear and tear — particularly in safety-critical areas like brakes, suspension, tyres, and steering. The good news is that most of these issues can be identified early through regular inspections and servicing.
Here are the most common MOT failures in the UK.
1. Worn or Faulty Brakes
Brakes are one of the leading causes of MOT failures. Because they are essential for safety, even minor faults can result in a fail.
Common brake-related failures include:
- Worn brake pads below legal limits
- Damaged or heavily corroded brake discs
- Brake imbalance between wheels
- Brake fluid leaks
- Handbrake inefficiency
If your car makes grinding or squealing noises, or you feel vibration when braking, it’s worth having your brakes checked before your test, to prevent MOT failure.
2. Suspension Wear and Damage in MOT Failures
Suspension problems are another major cause of MOT failure. The suspension system keeps your tyres in contact with the road and supports vehicle stability.
Common suspension failures include:
- Worn shock absorbers
- Broken or corroded springs
- Excessive movement in suspension joints
- Damaged control arms or bushes
Suspension wear often develops gradually, so drivers may not notice it immediately. However, signs like knocking noises over bumps or uneven tyre wear should not be ignored.
3. Tyres Below Legal Tread Depth
Tyres must meet the UK legal minimum tread depth of 1.6mm across the central three-quarters of the tyre.
Tyre-related MOT failures include:
- Insufficient tread depth
- Uneven tyre wear
- Cuts, bulges, or exposed cords
- Incorrect tyre size or type
Tyres are easy to check yourself before an MOT. A simple tread depth gauge can quickly confirm whether they meet legal standards.
Uneven tyre wear may also indicate issues with suspension or wheel alignment.
4. Lighting and Electrical Faults
Surprisingly, faulty lights are one of the simplest yet most common MOT failures.
This includes:
- Blown bulbs
- Brake lights not working
- Indicators failing
- Headlights misaligned
- Number plate lights not functioning
Because lighting faults are quick and inexpensive to fix, checking all lights before your MOT test can prevent an unnecessary MOT failure.
5. Steering Problems and MOT Failures
The steering system must be secure and responsive. MOT testers check for excessive play, damage, and secure mounting.
Common steering failures include:
- Loose steering components
- Worn track rod ends
- Power steering fluid leaks
- Excessive free play in the steering wheel
If your car pulls to one side or feels unstable at speed, it’s worth having steering and wheel alignment checked before your MOT.
6. Windscreen and Visibility Issues
Your view of the road must be clear and unobstructed.
Failures may occur due to:
- Large chips or cracks in the driver’s line of sight
- Worn or damaged wiper blades
- Washer system not functioning
- Obstructed view from stickers or damage
Even relatively small windscreen cracks can cause an MOT failures if they are within the driver’s field of vision.
7. Exhaust and Emissions Problems
Vehicles must meet legal emissions standards during the MOT test.
Failures can be caused by:
- Exhaust leaks
- Excessive smoke
- Faulty catalytic converters
- Engine management light being on
Regular servicing and diagnostics checks can help prevent emissions-related MOT failures.
How to Reduce the Risk of MOT Failures
The majority of the most common MOT failures are linked to general wear and tear. Keeping up with routine servicing allows technicians to spot issues early — particularly in brakes, suspension, tyres, and steering components.
Before your MOT test, you can:
- Check all lights
- Inspect tyre tread and pressure
- Listen for unusual noises
- Address warning lights promptly
Catching problems early often means simpler and less expensive repairs.
Final Thoughts
The most common MOT failures in the UK typically involve brakes, suspension, tyres, steering, and lighting — all essential safety systems.
The good news is that many of these failures are preventable with regular servicing and early inspections. Preparing properly before your MOT test not only increases your chance of passing first time but also keeps your vehicle safe and roadworthy throughout the year. Book your next MOT with D&G Autocare today, for a thorough and reasonably priced check of your vehicle.
