How does a windshield-washer pump work?

A windshield washer pump is a motorised, or electrical, part responsible for injecting stored windshield washer fluid directly onto the car windshield. The windshield washer pump pressures this stored water and injects it with enough force to cover the entire windshield surface.

Connected to Windshield Fluid Reservoir

The windshield wiper fluid is stored in a plastic reservoir underneath the car bonnet. The motorised windshield washer pump is connected to this reservoir by rubber hoses, which are responsible for transporting the windshield wiper fluid to and from the windshield washer pump.

Manual Activation of Windshield Washer Pump

The windshield washer pump is controlled manually from a button or switch located inside the car, normally located on the windshield wiper control arm. When this button or switch is activated, the windshield washer pump is activated and sucks stored windshield wiper fluid from the plastic reservoir into the pump itself. This fluid is then pressurised by the spinning of the motorised washer pump and propelled towards the car windshield.

Washer Fluid Channels

As the pressurised windshield wiper fluid leaves the windshield washer pump, it travels through a length of inner tubes, or channels, that direct this fluid to an open point near the bottom of the windshield wiper blades, from where it ejects and sprays onto the windshield.