Windshield Washer Fluid

If you live in a rainy or snowy climate, you have probably had your windshield splashed by a passing car or truck. When you are driving down the highway in stormy conditions or at higher rates of speed, you really do not have much time to react. On their own, your windshield wipers may not be able to handle the gobs of mud or salty slush that other cars throw onto your windshield, but a quick shot of windshield washer fluid can bail you out. That’s when you will be glad you paid attention to your windshield washer fluid level.

What is Windshield Wiper Fluid?

Windshield washer fluid is used to clean dirt, mud, bugs, and other debris off of your windshield. Unlike fuel or motor oil, the same type of fluid can be used by all cars so there is no need to be concerned about classifications or ratings. The fluid is typically 90 to 95 percent water with chemicals added to both clean and prevent freezing.

Washer fluid is sprayed onto your windshield from the reservoir with an electric pump through the windshield washer nozzle positioned below the windshield. These pinholes in the nozzles where the fluid shoots out can sometimes become clogged or obstructed by dirt and debris. If a clog is preventing your fluid from being dispensed, you can usually clear the windshield washer nozzle with a sewing needle or pin.

Some vehicles have a rear wiper in addition to windshield wipers. Whether you have a rear wiper or not, the same washer fluid reservoir is usually used. If you have an older SUV or other type of vehicle with a rear wiper, however, there may be a separate windshield washer tank or reservoir for the rear window in the trunk area. If you have a rear wiper, check your owner’s manual for the location of the windshield washer reservoir or reservoirs to be sure.

Buying Windshield Washer Fluid

Topping Up the Windshield Washer Fluid

You can buy windshield wiper fluid just about anywhere. You will often see it for sale in grocery or convenience stores, in auto parts stores, and in gas stations. You can also buy it online.

Windshield washer fluid is sold in both a regular formula which is ready to use right out of the bottle and a concentrated form. There are also other formulations targeting specific uses such as deicing or bug removal.

If you buy the concentrate, make sure you carefully follow the manufacturer’s instructions for mixing it with water. If you buy the standard, ready to use type you definitely do not want to mix it with water as it may become susceptible to freezing. If you live in a cold climate, buy the winter formula with deicer as it contains additives that will prevent the washer fluid from freezing in -20 degree temperatures or lower.

How to Add Windshield Washer Fluid

Adding windshield washer fluid is a simple maintenance task that anyone can do in just a couple of minutes. All you need is your jug of windshield wiper fluid. A clean funnel is helpful to prevent splashes and spills. To add windshield wiper fluid:

Open the hood of your car.
Locate the windshield washer fluid reservoir. The cap may have the windshield washer symbol you are probably familiar with on it, but it may not. If your fluid level is low but not empty, you may be able to see the blue fluid through the plastic reservoir.
Remove the cap and place your funnel down into the reservoir.
Pour the washer fluid into the funnel being careful not to overfill.
Remove the funnel and replace the cap.

When adding wiper fluid, be careful not to mistake the engine coolant container for the windshield washer container. Engine coolant is typically orange, green, or yellow. If you are not sure which is which, check your owner’s manual. Also, leave a little room at the top for the fluid to expand if the temperature outside is very cold.

Homemade Windshield Washer Fluid

Despite the fact the windshield washer fluid is extremely inexpensive and widely available, some people would prefer to make their own. The typical homemade windshield washer recipe calls for distilled water and some sort of detergent such as glass cleaner or dishwashing liquid or both. If you want to spend your time making homemade windshield wiper fluid just to save money, you are probably kidding yourself. If you object to the not so environmentally friendly chemicals that make up 5 to 10 percent of most commercially available windshield washer fluids, you have a point. If you opt to make your own and you live in a cold climate, make sure your recipe includes an ingredient that will prevent your homemade windshield washer fluid from freezing.

Can I Just Use Water Instead of Windshield Washer Fluid?

Using water instead of windshield wiper fluid is not a good idea for a few reasons. Without some sort of agent to prevent freezing, the water in your fluid reservoir could freeze which could lead to failure of your washer fluid system and a costly repair. Even if you live in a warm climate where freezing is not an issue, you should know that over time bacteria will thrive in warm water. Further, a study in the UK linked the use of water instead of windshield washer fluid to increased risk of contracting Legionnaires' disease. Lastly, water is simply not as effective against the mud or grime that can get propelled onto your windshield and you don’t want to be temporarily blinded at highway speeds.