Why Windscreen Washer Fluid Matters in MOT Testing

When preparing for an MOT test, most drivers focus on tyres, brakes, and lights. However, something as simple as windscreen washer fluid can cause your vehicle to fail. The MOT test ensures vehicles are safe and roadworthy, and visibility is a key part of this. A working washer system is essential for keeping your windscreen clear of dirt, rain, and road debris.

Can a Lack of Washer Fluid Really Cause an MOT Failure?

Yes – if your washer system doesn’t work during the MOT inspection, your car can fail. Even if everything else passes, insufficient or empty washer fluid means your windscreen cannot be properly cleaned. MOT testers check that the washer system sprays fluid effectively and covers the screen. If it doesn’t, this counts as a visibility fault.

Common Reasons for Washer System Failures

There are several reasons why a car may fail its MOT due to washer fluid:

• Empty reservoir: Simply forgetting to top up fluid is the most common cause.
• Blocked jets: Dirt, limescale, or frozen fluid can clog spray nozzles.
• Faulty pump: If the pump isn’t working, fluid won’t reach the windscreen.
• Leaking hoses: Cracks or splits in the pipes prevent fluid from reaching the jets.
• Frozen fluid: In winter, using plain water instead of proper screen wash can lead to freezing.

All of these issues are easy to prevent with basic maintenance.

How to Avoid MOT Failure Due to Washer Fluid

Fortunately, preventing this type of MOT failure is simple:

1. Top up before the test: Always fill your washer reservoir with proper screen wash, not just water.
2. Check spray jets: Test the system to make sure it sprays evenly across the windscreen.
3. Inspect hoses and pipes: Look for leaks or weak spray pressure that could indicate a problem.
4. Use winter-ready fluid: Screen wash with antifreeze properties prevents freezing in cold weather.
5. Regular maintenance: Make it a habit to check fluid levels weekly, especially before long journeys.

These quick checks can save you from an unnecessary MOT failure.

Other Visibility-Related MOT Issues

It’s not just washer fluid that affects your MOT result. Testers also inspect:

• Windscreen wipers: They must clear the screen effectively without smearing.
• Windscreen condition: Chips or cracks in the driver’s line of sight can cause a failure.
• Rear-view mirrors: These must be securely fitted and provide a clear view.

Since visibility is directly linked to road safety, these elements are always taken seriously.

Final Thoughts

While it may seem minor, washer fluid plays a bigger role in MOT compliance than many drivers realise. Forgetting to top up or overlooking small faults in the washer system can lead to a failed test and the hassle of a retest. A few minutes of preparation before your MOT can save time, money, and stress – ensuring your vehicle remains roadworthy and compliant.