Bob's Mechanical Repairs

Windscreen washer not working — MOT failure explained

Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].

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The washers can't deliver enough fluid to clean the screen with the wipers. It's a Minor defect, but it's a genuine fail and it's on the list of things that catch people out — plenty of cars arrive with an empty bottle in summer.

Wording as it commonly appears on an MOT certificate: “Windscreen washer providing insufficient washer liquid”.

What does it mean?

The washers can't deliver enough fluid to clean the screen with the wipers. It's a Minor defect, but it's a genuine fail and it's on the list of things that catch people out — plenty of cars arrive with an empty bottle in summer.

How serious is it?

Usually recorded as: Minor. The tester assesses the actual vehicle on the day, so your certificate is what counts.

What normally causes it?

  • An empty reservoir, which is the single most common reason
  • Blocked jets, often from wax after a car wash or from frozen residue
  • A failed washer pump, or a blown fuse shared with something else
  • A split reservoir or a pipe knocked off behind the bumper — the bottle empties itself overnight

What a mechanic would check

Fill it, try it, and listen. Pump buzzing but nothing coming out means a blockage or a disconnected pipe; total silence means power, fuse or pump. A pin through the jet clears most blockages, and I always aim them back onto the swept area afterwards.

What might need replacing

  • Screenwash
  • Jet cleaning or new jets
  • A washer pump
  • A pipe or reservoir repair

Can you still drive it?

Fine mechanically, but a salted, filmed-up screen into low winter sun is genuinely dangerous. Keep the bottle topped up with proper screenwash, not water, so it doesn't freeze.

More visibility failures · MOT failure decoder · Ask a mechanic about your certificate

This is general guidance from a UK mechanic, not a substitute for a physical inspection. Only the tester who inspected your vehicle can confirm what was recorded and why.

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