Wiper/Washer Systems: Operation

The basic washer pump is a spring loaded piston enclosed in a plastic cylinder housing. An actuator plate extends from the cylinder housing. A valve assembly, consisting of 2 exhaust and 1 intake check valve, is attached to the end of the cylinder housing.

A tang on the piston actuator plate holds the plate in a lock-out position so there is no pumping action. To start the pump, push washer button to energize the relay. This pulls the relay armature toward the coil, allowing the ratchet gear pawl to engage the ratchet gear and begin rotation. This sequence starts pumping action.