MOT Windscreen & Wiper Checks: Avoid Failure

The annual MOT test is a crucial hurdle for every vehicle owner in the UK, ensuring our roads remain safe for everyone. While many drivers meticulously check their tyres, brakes, and lights, one area often overlooked, yet critically important, is the condition of your car's windscreen and its accompanying wiper system. Issues with visibility can lead to an automatic MOT failure, making a thorough pre-test inspection of these components absolutely essential. This guide will delve into the specifics of what MOT examiners look for, helping you understand how even minor damage or worn parts can impact your test outcome, and most importantly, how to avoid common pitfalls.

Understanding Windscreen MOT Requirements

Your car's windscreen is more than just a barrier against the elements; it's a fundamental safety component that directly impacts your ability to see the road clearly. The MOT test places significant emphasis on its condition because impaired visibility can lead to dangerous driving situations. It's not just about obvious cracks; even small chips or worn-out wipers can be the difference between a pass and a fail.

Can a Cracked Windscreen Fail an MOT?

Yes, a cracked windscreen absolutely can lead to an MOT failure, but it’s not an automatic disqualification. The outcome hinges on two primary factors: the size of the crack and its location on the windscreen. This distinction is crucial, as what might seem like a minor blemish to you could be a significant safety hazard in the eyes of an MOT examiner.

If your windscreen has a crack exceeding 40mm in diameter, regardless of its position, your car will unequivocally fail its MOT. This size of damage is considered to severely compromise the structural integrity of the glass and significantly impair the driver's view. In such cases, a repair is often insufficient, and a complete windscreen replacement is typically required before re-presenting the vehicle for its test.

For cracks smaller than 40mm, the situation becomes more nuanced. The windscreen is divided into specific zones relative to the driver's eye line, and the crack's location within these zones determines the MOT outcome:

• Zone A: This is the most critical area, a 290mm wide strip centred on the steering wheel and extending from the bottom of the windscreen to the top, directly in the driver's line of sight. Any crack larger than 10mm within Zone A will result in an MOT failure. Even minor damage here is considered a direct impairment to visibility.
• Zone B: This zone covers the rest of the area swept by the windscreen wipers, outside of Zone A. A crack larger than 40mm in Zone B will also lead to a failure. However, if the crack is between 10mm and 40mm in Zone B, it may result in an advisory notice, meaning it passed but a repair is recommended.
• Zone C & D: These zones are outside the swept area of the wipers or not in the driver's direct line of sight. Damage here is less likely to cause a failure unless it's exceptionally large and compromises the overall structural integrity of the windscreen.

It’s always advisable to address any cracks promptly. Even a small crack can quickly propagate, especially with temperature fluctuations or impacts from potholes, turning a minor issue into a costly replacement.

Is a Chipped Windscreen an MOT Failure?

Similar to cracks, whether a chip results in an MOT failure depends on its size and location. Chips are generally smaller than cracks, meaning they are less likely to fall into the automatic +40mm failure category. However, their position on the windscreen remains paramount.

A chip larger than 10mm in Zone A (the critical driver's eye line area) will typically lead to an MOT failure. For chips smaller than 10mm within Zone A, it often comes down to the examiner's discretion. If they believe the chip significantly impairs the driver's visibility, even if small, they may issue a failure. Conversely, if it's deemed minor and not obstructive, it might receive an advisory.

In Zone B, a chip larger than 40mm will fail. Chips between 10mm and 40mm in Zone B will usually result in an advisory. Chips in Zones C and D are less likely to cause a failure unless they are very large or numerous.

While chips might seem insignificant, they are often precursors to larger cracks. The internal stresses within the glass, combined with external factors like extreme temperatures or road vibrations, can cause a small chip to spiderweb into a major crack very quickly. Addressing chips with a resin repair, often a much cheaper and quicker fix than a full replacement, is highly recommended as soon as they appear.

The Role of Windscreen Wipers in Your MOT

Beyond the glass itself, the functionality of your car's windscreen wipers is a critical component of the MOT. They are your primary means of maintaining clear visibility in adverse weather conditions, and their proper operation is non-negotiable for road safety.

Are Windscreen Wipers Part of MOT?

Absolutely! The front windscreen wipers are an integral part of the MOT test. Examiners will meticulously check their condition and effectiveness. The blades must be capable of clearing the windscreen efficiently, removing moisture and dirt without leaving streaks, smears, or unwiped areas that could compromise the driver's view.

Key aspects of the wiper check include:

• Blade Condition: The rubber wiper blade must be smooth, supple, and free from splits, tears, or excessive wear. Damaged blades often fail to make proper contact with the glass, leading to poor clearing.
• Wiper Arm Functionality: The wiper arms must operate correctly through their full sweep, without sticking or making excessive noise. They should also be securely attached and not obstruct visibility when stationary.
• Washing System: The windscreen washer system must work, delivering an adequate spray of fluid to the windscreen. Without screen wash, the wipers cannot effectively clean the glass, especially when dry or dealing with stubborn dirt.

A week or two before your MOT, make it a point to inspect your front wipers. Lift the wiper arms away from the windscreen and run your finger along the rubber blade. Does it feel smooth? Are there any nicks or hardening of the rubber? Operate the wipers with screen wash to observe their performance. If they judder, squeak, or leave streaks, it's a clear sign they need replacing. Replacing wiper blades is a straightforward DIY task that can save you an MOT retest fee.

Will a Faulty Rear Wiper Fail an MOT?

This is a common question, and the answer might surprise some: no, you cannot fail your MOT for a faulty or worn rear wiper. Unlike the front windscreen wipers, a rear windscreen wiper is not a legal requirement for vehicles in the UK. Many car models, particularly older ones or certain saloon cars, do not even come equipped with a rear wiper from the factory.

Because it's not a legally mandated safety feature, the condition or functionality of your rear wiper is not part of the standard MOT inspection. So, if your rear wiper is broken, missing, or simply not working, it will not result in an MOT failure.

However, while it won't fail your MOT, it's still highly advisable to maintain your rear wiper in good working order. Clear rearward visibility is crucial for safe driving, especially when reversing or in heavy rain. Neglecting a worn rear blade can also lead to more serious issues, such as the metal wiper arm scratching the glass. Such scratches can permanently impair visibility and significantly reduce your car's resale value, making a simple blade replacement a wise investment.

The Importance of Screen Wash

Often overlooked, but absolutely critical for your MOT, is the presence and functionality of your screen wash system.

Will I Fail My MOT if I Don’t Have Any Screen Wash?

Yes, this is a guaranteed failure. If your windscreen washer system does not produce fluid, or if the reservoir is empty, your car will fail its MOT. The logic is simple: without screen wash, your wipers cannot effectively clear the windscreen of dirt, grime, or road spray, especially when the vehicle is in motion. This directly compromises visibility and is deemed unsafe by the DVSA (Driver and Vehicle Standards Agency).

Topping up your screen wash reservoir is one of the simplest pre-MOT checks you can perform. It takes mere minutes and can save you the hassle and cost of a retest. Make sure to use a good quality screen wash concentrate diluted with water, as plain water can freeze in colder temperatures and isn't as effective at cleaning.

Summary of Visibility-Related MOT Outcomes

To help clarify the various scenarios, here's a quick reference guide:

Frequently Asked Questions About Windscreen & Wiper MOTs

Here are some more common questions drivers have regarding their windscreens and wipers and the MOT test:

What if my windscreen crack is repaired before the MOT?

If a crack or chip is repaired professionally using resin, the repair itself will be assessed. The repair must be sound, not obstruct the driver's view, and not discolour significantly. A well-executed repair, even if visible, will usually pass as long as it meets the size and zone criteria for an intact windscreen.

Can a dirty windscreen cause an MOT fail?

While an excessively dirty windscreen might make it difficult for an examiner to properly assess the glass for cracks or chips, a dirty screen alone won't fail the MOT. However, if the dirt is so severe that it obstructs visibility to the point of being unsafe, or if it prevents the examiner from seeing critical areas, they might advise you to clean it and re-present the vehicle. More critically, if your screen wash system isn't working to clear that dirt, then it's a definite fail.

Do I need to check my wiper fluid level before the MOT?

Absolutely, yes! As mentioned, an empty screen wash reservoir or a non-functioning washer system is a guaranteed MOT failure. It's one of the easiest checks to perform and easiest failures to avoid. Always top it up before heading to the test centre.

What if my wipers are noisy or juddering but still clear the screen?

Noisy or juddering wipers are a strong indication of worn blades or an issue with the wiper mechanism. While they might still technically clear the screen, an examiner could deem them as impairing visibility due to inconsistent contact or excessive noise distracting the driver. This often results in an advisory, recommending replacement, but in severe cases, it could lead to a failure if visibility is significantly compromised.

Are heated windscreens checked in the MOT?

While the functionality of a heated windscreen element isn't directly tested, any damage to the windscreen itself (cracks, chips) that might be caused by or affect the heating elements will be assessed under the standard windscreen criteria. The heating elements themselves are not part of the mandatory MOT check.

What if my car doesn't have a rear wiper?

If your car was manufactured without a rear wiper (common on many saloon cars), then there's absolutely nothing to worry about. The MOT only checks components that are present and legally required for the vehicle type. Since rear wipers aren't legally required, their absence is not an issue.

How often should I replace my wiper blades?

It's generally recommended to replace your wiper blades every 6 to 12 months, or sooner if you notice signs of wear such as streaking, chattering, or unwiped areas. Regular replacement ensures optimal visibility and reduces the risk of an MOT failure or, more importantly, an accident due to poor visibility.

Final Thoughts on Visibility and Your MOT

Ensuring your windscreen is clear and your wipers are in top condition is not just about passing your MOT; it's fundamentally about your safety and the safety of other road users. A small investment of time in checking these components before your test can save you from the inconvenience and expense of an MOT retest.

Remember, while a faulty rear wiper might not fail your MOT, maintaining all aspects of your vehicle, including those not legally mandated, contributes to a safer and more enjoyable driving experience. Prioritise clear visibility, and you'll not only sail through your MOT but also drive with greater confidence and security.