How to Check a Car Before it’s MOT Test

Whilst doing my training for Halfords I have learnt that the majority of cars fail their MOT test on really stupid things like bulbs and tyre wear. With the MOT just around the corner on my Mercedes I thought this would be the perfect opportunity to show you the best way to check a car before its MOT.

Firstly, turn the key to the second ‘click’ and all the warning lights should light up like so:


Now, start the car and they should all turn off apart from the handbrake light. If any more remain on then they will be the first things you need to address.

The next thing is to check your lights. Turn your hazard lights and side lights on first then walk around the car making sure each bulb is working as it should. Then turn on your main headlights and inspect the car. Repeat the process for full beam, fog lights etc. Make sure to check any number plate lights. These can be easily missed.


Once you have established they are all working enlist the help of a friend to check your brake and reverse lights. Get them to stand behind the car whilst you apply the brake and go into reverse. If all lights are working correctly then that is good.

Tyres are another easy check that a lot of cars seem to fail their MOT on. The easiest way to check that you have the legal tread requirements is with a 20p piece.


As you can see a 20p coin has a lip going around the outside of it. The lip is about 1.6mm deep which is the legal minimum tread requirement. Now run your hand in the tread grooves of your tyre and you will feel a slight raised section. Put the 20p on top of this. If you can see the lip then you will need a new tyre.


Brakes are another thing that cars commonly fail on. You don’t have to remove the wheel to test the condition of your brakes, the MOT test centre normally won’t, but I find it a little easier to.


There is normally a little bit of a groove on the disc where the friction from braking wears it away. If that is noticeably deep then it is probably best to get new discs.

Brake pads tend to need replacing more often as they are made out of a softer material. You will be able to see them sitting between the brake caliper and the disc. If they are 5mm or thinner then it will be soon be time to replace them. These have plenty of life left in them


Whilst the car is in the get a hold of your suspension arms and try to wiggle them left to right. If they move then the bushings are in need of replacing. You can also check your exhaust for any cracks or holes. A little surface corrosion is to be expected but holes will be a fail


If there is a hole you can buy Fire Gum which is an exhaust repair kit. It will seal any any small holes. Any big holes will require welding or may mean that section of exhaust will need to be replaced.

Put the wheels back on but before you lower the can try to make them wobble back and forth. If they wobble then you may need a new wheel bearing which isn’t fun!

Now to test the handbrake. Most manual cars will have their hand brakes in constant use for hill starts and such so you should know if there is an issue. Most people with automatics seem to put them in park and leave the hand brake off. It will need to be working for your MOT so make sure to check it. To test a handbrake find a steep hill, pop the car into neutral and apply the parking brake. If the car rolls down the hill then it isn’t working properly. If the brake holds it then you should be ok.

Finally make sure to check the condition of your wiper blades and the amount of screen wash you have. If the washers don’t spray any liquid then you need to put some screen wash in and if the wipers leave smears then you will need to replace them. It’s a super simple check and repair.


That’s just about everything you can check yourself! Best of luck with your MOT!

Thanks for reading

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