Check your screen-wash strength

Posted on December 10th, 2019 by Rob Marshall

Check your screen-wash strength

As winter is now firmly upon us, GEM Motoring Assist is advising that drivers not only check their screen-wash levels but also the fluid concentration. Frozen screen-wash not only will stop you from clearing your windscreen but it can also damage the system’s pump and jets.


Anti-freezing properties

The chief property of most screen-washes is to reduce the temperature at which the liquid freezes. The most expensive option is to buy pre-mixed screen-wash, which you simply pour-into the reservoir. The cheapest screen-washes tend to smell pretty vile and protect to only a few degrees below zero, even when used neat. Be aware that the anti-freezing properties of any screen-wash fluid will be reduced, should you add it to a reservoir that contains a quantity of water already. Most screen wash solutions require diluting with water, or can be used neat for maximum anti-freezing protection. Therefore, follow the dilution instructions carefully (see picture), which tend to differ between manufacturers.


Yet, there are other issues, too. Cheap screen-washes can damage plastic headlamp covers, so ensure that you buy decent quality solution from a reputable supplier. Consider also that some screen-wash types do not mix together very well and can create a gloop that blocks the fine filters that are used on some models. Using your screen-wash facility until the water runs out is the easiest DIY way of emptying most of the system, without either dismantling, or sucking out the old fluid. Finally, never use anti-freeze that is designed for engine cooling systems. Not only is it not very effective at clearing glass but it also damages paintwork.


Watch our video on how to top up your screen wash for more information.