Practical guide
How to Check Coolant & Screenwash
Simple level checks with an important safety boundary around a hot, pressurised cooling system.
Never open a hot pressurised cooling system; allow it to cool and follow the handbook.
What matters in practice
Coolant and screenwash are both simple checks, but they do different jobs.
Check the coolant level only when the engine is cold and make sure it sits between the MIN and MAX marks. If the level keeps dropping, don’t just keep topping it up — repeated coolant loss needs investigating.
Screenwash is less critical mechanically, but it matters for visibility. Keep it topped up with a suitable screenwash mixture, especially in winter when plain water can freeze.
What to do next
If either level is low, top it up with the correct fluid and recheck it afterwards.
For coolant, use the correct specification for the car and never open a pressurised cooling system while it’s hot. If the coolant level drops again, there may be a leak or another fault that needs attention.
Screenwash is straightforward: refill the reservoir, test the washers and make sure the jets clear the windscreen properly.