MOT failure: Top 5 reasons and what to do if your car fails

Having you car fail its MOT can be incredibly annoying. If you've followed our pre-MOT checklist, you'll probably have a good idea about whether or not your car will pass or fail. But even without the surprise, the repair bill you'll be lift with still won't be welcome. 

We've listed some common reasons for MOT failure in this guide, and outlined key steps you can take if your car doesn't pass its test.

In This Guide:

• Top 5 reasons for MOT failure
• What happens if your car fails its MOT?

Top 5 reasons for MOT failure

Lighting and signalling

Lighting and signalling issues account for a whopping 18% of all MOT failures. This is despite the fact light replacements are, for the most part, some of the cheapest and easiest fixes on your car. You can change them yourself if you have the owner's manual but many garages will also change bulbs for a small fee, and some for free!

Another reason you might fail based on your lighting and signalling is if you have headlight deflectors fitted to your car for driving in europe, so make sure you remove these when you come back from the continent!

Driver's view of the road

Having cracks and chips in your windscreen which obscure the driver's view is a sure fire way to fail an MOT, but many driver's don't realise that you can also fail if you have items obscuring the view, so avoid placing stickers, phone cradles or bluetooth headsets in the windscreen for your test. Some car insurance policies will cover repairs to your windscreen, so if you have a crack it's worth checking with your insurance provider.

At least one of your wing-mirrors, as well as your rear view mirror, must be also clean and undamaged. replacement stick on mirror surfaces can be purchased very cheaply.

Your view of the road extends to your windscreen wiper blades and washers as well so be sure to fill up the fluid and test that the wipers clear the windscreen effectively before your test. The rubber on your wiper blades should be replaced, a cheap fix, if it is at all damaged or more than a year old.

Tyre condition and pressure

Around 10% of MOT fails are due to tyre issues. It's vital that tyres have the correct pressure and enough tread depth to allow you to effectively stop in the event of an emergency, so they should be regularly checked. If the tyres show any sign of damage, bulging, or the tread is less than 1.6mm your car will fail it's MOT.

Brake issues

Make sure you check your brakes before an MOT. If the braking feels spongey or the steering pulls to either side when braking it could be a sign that the pads or discs are worn and may need replacing. Dependent on the conditions you drive in, brakes can wear out quite quickly, for example in hilly areas, or last a long time if you often drive slowly and rarely have to operate them. On average brakes need replacing around every 50,000 miles.

Suspension

Suspension failures are fairly common in Britain, owing to the fact our roads are often potholed and bumpy. There's not a lot you can do to predict a suspension failure, and either way it's a tough fix that you'd most likely want to have done by a professional anyway. You can maintain your suspension by driving carefully and trying not to hit every bump in the road at speed.