The most common MOT failures and how to avoid them

An MOT Test is an annual test of vehicle safety, roadworthiness and emissions that is required in the UK for vehicles over three years old. It will determine if your vehicle meets the minimum road safety and environmental standards required by law.

The test is designed to make sure the driver, any passengers and other road users are safe when the vehicle is on the road.

If you want to find out more about the MOT Test and what it entails, click here to read our comprehensive guide to MOTs. If your MOT test is coming up, and you want to ensure it passes first time, read below to see the most common MOT failures and learn what to do to avoid or rectify them.

One in 5 cars will fail their MOT because of issues with lights. 

On your MOT Test, all lights from side lights to indicators and even the number plate light are checked. Blown bulbs account for the majority of failures relating to lights, but the condition of the lights can also play a factor.

Plastic casing can get misty over time, and any cracks or damage to the casing will also result in a failed MOT.

Turn on all the lights and take a good walk around the car to see if they are all working. You also need to check your indicators, so be sure to have another walk round while these are on.

Don't forget to have a look at your number plate light as well - this one is easily forgotten!

Ask someone to sit in the car and press the brake pedal. Do the lights illuminate as they should? And what about if they put the car in reverse? Are your reversing lights working properly too?

Next, inspect the actual light casing. If you notice any crack or damage, you will need to get this replaced. If the casing is looking a little misty, you can purchase kits that will clean it up without needing to buy a new one. 

We can probably blame the pot holes and uneven roads for most of our suspension issues, and unfortunately suspension is not the easiest to check at home, so it's not a surprise that over one in 10 MOT failures are caused by suspension issues. 

Leaky shock absorbers, or snapped springs might not be easy to identify unless the car is on a ramp but there are a few checks you can do to give yourself an idea as to how your suspension system is performing.

The first thing to look out for is any clunks or bangs as you're driving; particularly if you're turning a corner or going over a bump. Not all noises will necessarily be suspension, but they are always worth investigating.

When your car is parked, does it look like it is sitting level? If it appears to be dropping down or sitting higher in one corner, you might have an issue with the suspension.

Take a walk around the car and push down on each corner. When you let go, it should return to its normal position easily. If there's any excess bounce, or it doesn't move back easily, there may be a suspension issue.

Problems with car suspension are most easily identified when up on a ramp, so we would always advise timing your annual service just before your MOT Test. A qualified technician will already have the car in the air and will be able to identify any potential issues that you can address before putting your car through its MOT.

There is no set interval you should change your brakes, as their wear and tear is most affected by driving style, frequency, weathering and so many other variables.

The braking system is responsible for stopping the car, making it one of the most vital elements and crucial to ensure it's all in working order.

On an MOT test, your brake pads, discs and even the handbrake will be tested to ensure they are doing their job properly.

Listen out for any squeaking or grinding from your brakes as this could be a sign the brake pads are running low.

If you brake, do you notice any pulling to one side or does your car stop in a straight line? Does the brake pedal feel spongy? These are also signs that you might need to check if your brakes need replacing.

You may want to inspect the brakes yourself, so you'll need to remove the wheel and have a close look.

The brake disc should be smooth, with no lips or damage. The brake pads should be nice and thick with plenty of pad remaining.

To check your handbrake, stop the car on a hill and apply the handbrake. Does the car start to roll? If not, you should be okay but if it does, you may need to get it adjusted.

Tyres are crucial for your car's safety and should be checked regularly, not just when it's time for your MOT. 

They should be free of any damage, have over 1.6mm of tread with even wear and be inflated properly at all times. 

Even small cuts and snags have the potential to cause a major accident and put your safety at risk.

The best place to start is with tyre tread. Your car needs a minimum of 1.6mm of tread across the central three quarters by law.

We would recommend changing your tyres at around 3mm for maximum safety.

To test the tyre tread, you can you a 20p coin. Place it into the tread and if you can see the outer band, then your tread is too low and the tyre needs replacing. You could also be fined up to £2,500 and get 3 points on your licence per tyre, so it's always worth getting them changed.

Check to see if the wear is even - anything uneven could indicate another issue, like poor inflation or wheel alignment. It's also worth checking for lumps, cuts or any other damage.

Make sure you're checking the whole tyre and not just the part you can get to when it is parked in one position.

The final thing to check is that you actually have the right size and speed rating tyres suitable for your car. You can usually find the recommended size in your handbook - and the tyre size should be matching across each axle.

Anything blocking the windscreen, and certainly anything in the driver's eyeline will result in an MOT failure. 7.2% of MOT failures fall foul of this.

Anything from air fresheners to aftermarket sat navs could be considered to be interfering with the driver's visibility.

The windscreen and windscreen wipers will also play a part here.

Start by removing anything like air fresheners, sat navs or anything else that has the potential to be distracting the driver.

Next check your windscreen - are there any chips or cracks? Cracks should be dealt with immediately, chips may be forgiven on an MOT Test but only if they are deemed to be in the driver's eyeline. It's still worth getting these sorted as soon as you can so they don't worsen.

Check your windscreen wipers are working effectively and are clearing the screen. It might also be wise to top up your washer fluid before your MOT as well!

Those are some of the most common MOT failures, but of course there are many other elements that could cause your car to fail the test. Here are a few extra that it's worth being aware of:

• Emissions - pre-MOT fuel treatment packs are available to clean out the fuel system, however on some older and particularly on diesel vehicles, the emissions test may be a tough one to pass
• Steering - Fluids are not generally check on an MOT, but the steering fluid is, so make sure you check levels
• Seat belts and air bags - Seat belts must retract and buckle in properly, and air bags must be on and free of faults.
• Rust - There's not much you can do about rush or corrosion, but any sharp edges will fail the MOT test. 
• Registration plates - your registration plate should be free of damage, and visible, so at least give it a wipe down before your MOT.

At both Bumpers Farm and MRG, on Bath Road, we are authorised MOT Test Centres in Chippenham.

We are authorised service centres for Citroen, Peugeot, SEAT, Kia, Ford, Volvo and Polestar, but all makes and models are welcome.

Click the button below or call us to book.

Bumpers Farm: 01249 444000

MRG: 01249 443300