How Do Auto Window Washers Work?

The Reservoir and Pump

The windshield washer reservoir is commonly and conveniently located in the engine compartment. Some vehicles with rear window windshield wipers may even have small reservoirs located near the rear wiper arm or wiper motor. The reservoir holds the washer fluid in it and has all the equipment plumbed into it to purge the fluid through small rubber tubes/hoses that connect to the windshield washer nozzles. The most important component attached at the bottom of the reservoir is the windshield washer pump. This is an electrical or vacuum powered pump and it is activated by an electrical switch located internally and conveniently on or near a lever of the steering wheel. If the pump fails for any reason, you will not be able to wash your windshield.

In the old days, there was one kind of fluid. In the winter, you'd add alcohol to it so it wouldn't freeze. Nowadays there's winter mix, summer mix, some that helps clean splattered bugs off, some that repels rain, and so on. It used to be fairly affordable and now because of all the different types and brand names, it can be expensive. You can still find affordable and functional windshield washer fluid, but the important thing is to buy the right kind for the right time of year. If you have a summer mix in your reservoir in the winter, it will freeze in the reservoir or in the rubber lines/hoses, leading to the windshield washer nozzles. Keeping a jug in your auto is useful for emergencies. while checking the reservoir before travel is helpful.

The hoses and nozzles are important aspects of the windshield washer system. Clogged or misaligned nozzles will not spray properly or strike the right area of the windshield and cracked or separated hoses will leak the fluid from the broken hose before the fluid gets to the nozzle. The rubber hoses run from the reservoir and commonly channel on the underside of the hood or along the inside fender rails in the engine compartment. Some may even snake through the skeletal cavity of the vehicle all the way to the rear wiper if applicable. One main hose may usually runs from the reservoir and branches off with simple plastic plumbing T's to both front nozzles and when applicable, a rear nozzle. (unless that runs off a different reservoir and pump as previously mentioned) Locating the hoses running from the reservoir in your car and follow them to the windshield washer nozzles will show you what a simplistic plumbing system it is and may help you troubleshoot it in the future. Often times, fixing a broken nozzle or cracked hose is very easy to do and requires little to no tools, depending on the application.