Most MOT failures aren’t expensive mechanical problems. They are bulbs, tyres, wiper blades and screenwash: things you can check or fix yourself in minutes. These guides cover the basic jobs, with the share of MOT tests that failed on each area in 2025 from our analysis of DVSA data.
How to change a car bulb
Step-by-step guide to replacing headlight, brake light, indicator and number plate bulbs yourself, plus how often lighting faults fail the MOT.
How to check your tyres
How to check tyre tread depth, set the right pressures and spot damage that fails the MOT, with the UK legal limits explained.
How to replace wiper blades and fix washers
How to change windscreen wiper blades, unblock washer jets and know when windscreen chips fail the MOT. Simple DIY fixes for visibility failures.
How to check brake pads and discs
How to check brake pad thickness and disc condition yourself, the warning signs of worn brakes, typical costs, and what fails the MOT.
How to check your car’s oil, coolant and fluids
A simple guide to checking and topping up engine oil, coolant, brake fluid, power steering fluid and screenwash, and what leaks mean for your MOT.
How to check your car’s suspension
How to spot broken coil springs, leaking shock absorbers and worn drop links, what each costs to fix, and which suspension faults fail the MOT.
How to check a car for rust
Where to look for rust on a used car, how to tell harmless surface rust from structural corrosion that fails the MOT, and how to treat minor rust yourself.
How to check and replace a car battery
How to test a car battery, jump start a car safely, and replace a battery yourself, including the order to disconnect terminals and when to call a garage.
Before your next test, run through our MOT preparation checklist, and check your car’s MOT history for advisories the tester flagged last time.