There’s a good chance you’ve never given your washer jets a second thought. They’re just there, sitting on your bonnet, doing the job whenever you flick the stalk. Out of sight, out of mind.
But new figures from the DVSA tell a different story.
According to the data, faulty windscreen washer jets led to a staggering 216,388 MOT failures in 2025! That works out at nearly 600 cars failing their tests every single day because of a part that costs (in most cases) less than a tenner to replace.
It makes you wonder – how many of those failures could have been avoided with a five-minute check and a splash of screenwash before their MOT booking?
Why are so many cars failing?
Well, it’s simple: most drivers just don’t think about their washer jets – let alone their importance to the MOT rest! In research done by eBay, 26% of motorists said they had no idea that faulty washer jets could lead to an MOT failure. And 69% of drivers said they wouldn’t feel comfortable replacing a faulty windscreen washer jet themselves.
But what about basic maintenance? One in five drivers said they would only check their washer jets when an MOT or service is already booked – and 13% said they never check them at all! Given that the MOT test states that your washer system has to work properly, that’s a gamble that isn’t worth taking.
Small and simple parts like washer jets can go under the radar – and tiny little things like this are causing a significant number of failed MOTs every year. But the good news is, all of these are preventable with cheap, easy fixes!
Block and roll
Blockages can cause your washer jets to stop working fairly rapidly. In the dusty months, dirt can build up inside, getting soaked when you activate the jets, then drying out again. If this process repeats enough times, you’ll end up with blocked jets that won’t work when they’re needed – and that’s an MOT fail. You can sometimes unblock them with something as simple as a pin or a needle, which can save you trouble later. But blocked jets are only half the problem.
Take aim
Now, we’ve all played that prank where you swivel the washer jet around, and squirt your mate standing next to your car with screenwash (haven’t we?), but if you don’t put them back before your MOT is due, you could be in trouble.
That’s because incorrectly aligned washer jets can also cause your car to fail the MOT test. Most drivers don’t realise this could cause a fail, or know how to adjust them correctly – unless they’d played the old swivel and squirt gag themselves… Starting to think we might be in the minority on that one.
Basically, your washer jets need to spray the windscreen in the right place, hitting the area swept by the wipers. If they’re firing over the roof, dribbling down the bonnet, or only hitting your mates, that’s a failure. The good news is that most jets can be realigned by hand, gently nudging the nozzle back into the correct position.
What to check before your MOT
The MOT covers a few specific things when it comes to your windscreen washing system:
Weak or no spray
If the wiper fluid isn’t reaching the screen properly, the jets may be blocked or broken.
Misaligned jets
The spray should hit the viewable area of the windscreen, not overshoot or fall short.
Blocked nozzles
Dirt can clog the jets over time, reducing effectiveness.
Low washer fluid
An empty washer fluid reservoir is an automatic MOT failure. It sounds basic, but it happens!
Pump issues
If you can’t hear the pump whirring when you activate the washers, there may be an electrical fault.
Leaks in the system
Any fluid pooling under the car or around the hoses needs investigating, and could lead to the cause of your problems.
The DVSA’s own data shows that visibility-related issues, including washer jets, account for around 8% of all MOT failures. That’s a big chunk of tests that could be saved with a little bit of testing at home. So, what can you do to help yourself?
How to fix it yourself
If you do find a problem, the fix is usually (but not always) easy.
Start by testing the jets. If the spray is weak or uneven, you probably have a blockage. Look at the jets on your bonnet or scuttle panel, and see if you can use a pin or paperclip to gently clear the nozzles. Test again and see if it improves.
If that doesn’t work, you might need to check the pipes. Open the bonnet, and find the hoses connected to the jets. Disconnect them, and use compressed air (or just blow through them) to clear any blockages further down the line.
For stubborn blockages, you can remove the jet entirely (they often just unclip) and soak it in white vinegar for a few hours. This dissolves gunk without damaging the plastic. Rinse, refit, and test the jets again.
If the jet is damaged beyond repair, replacements are cheap and available all over the place. Most cost between £1 and £30, with the majority coming in at under a tenner.
If it’s an electrical or pump fault, then that might be harder to diagnose. A reputable garage can help you find the root cause of your windscreen washing woes, and even this won’t break the bank – but even if it did, the long and short of it is that you just can’t drive around without a proper working washer system.
So, before your next MOT is due, give your washer jets a whirl. It could save you a wasted trip to the MOT test centre!
How to Book a MOT
Need to book a MOT test? Book yours with We Only Do MOTs. We promise to provide an impartial, independent MOT to everyone – and will carry out most minor repairs for free.
Send your message to enquiries@onlydomots.co.uk or call us on 023 8064 7180
