Windshield Washer Spray Nozzle: Description and Operation

WASHER NOZZLE

DESCRIPTION

FRONT




The fluidic front washer nozzles (2) are constructed of molded plastic and include an integral check valve. Each nozzle has two integral latches (3) that secure them in dedicated holes in the hood panel near the base of the windshield. The domed upper surface of the washer nozzle is visible on the outside of the hood panel, and the two nozzle orifices (1) are oriented towards the windshield glass.

An integral diaphragm type check valve is contained within the body of each nozzle. The washer plumbing fittings (4) for the washer nozzles extend below the hood panel and are accessible from the engine compartment.

The front washer nozzles cannot be adjusted or repaired and, if ineffective or damaged, they must be replaced.

REAR




The fluidic rear washer nozzle (4) is constructed of molded plastic. The rear washer nozzle is secured by an integral latch feature (1) and two integral alignment pins (5) within a mount integral to the lens of the Center High-Mounted Stop Lamp (CHMSL) on the outer liftgate panel above the rear flip-up glass opening.

The domed outer surface of the washer nozzle is visible on the lower exterior surface of the CHMSL, and a rubber O-ring (3) seals the nozzle to the lamp lens. The nozzle orifice is oriented downward towards the liftgate glass. The washer plumbing fitting (2) is concealed between the liftgate outer and inner panels.

The rear washer nozzle cannot be adjusted or repaired and, if ineffective or damaged, it must be replaced.

OPERATION

FRONT
The two front washer nozzles are designed to dispense washer fluid into the wiper pattern area on the outside of the windshield glass. Pressurized washer fluid is fed to each nozzle from the washer reservoir by the washer pump/ motor unit through a single hose, which is attached to a barbed nipple on each washer nozzle below the inner hood panel. A fluidic matrix within the washer nozzle causes the pressurized washer fluid to be emitted from the nozzle orifice as an oscillating stream to more effectively cover a larger area of the glass to be cleaned.

The integral check valve in each nozzle prevents washer fluid from draining out of the washer supply hoses back to the washer reservoir. This drain-back would result in a lengthy delay after the washer switch is actuated until washer fluid was dispensed through the nozzles, because the washer pump would have to refill the washer plumbing from the reservoir to the nozzles. Such a drain-back condition could also result in water, dirt, or other outside contaminants being siphoned into the washer system through the washer nozzle orifice. This water could subsequently freeze and plug the nozzle, while other contaminants could interfere with proper nozzle operation and cause improper nozzle spray patterns. In addition, the check valve prevents washer fluid from siphoning through the washer nozzles after the washer system is turned Off.

When the washer pump pressurizes and pumps washer fluid from the reservoir through the washer plumbing, the fluid pressure unseats a diaphragm from over a sump well within the nozzle by overriding the spring pressure applied to it by a piston. With the diaphragm unseated, washer fluid is allowed to flow toward the nozzle orifice. When the washer pump stops operating, the spring pressure on the piston seats the diaphragm over the sump well in the nozzle and fluid flow in either direction within the washer plumbing is prevented.

REAR
The rear washer nozzle is designed to dispense washer fluid into the wiper pattern area on the outside of the liftgate flip-up glass. Pressurized washer fluid is fed to the nozzle from the washer reservoir by the washer pump/ motor through a single hose, which is attached to a barbed nipple on the back of the nozzle. A fluidic matrix within the nozzle causes the pressurized washer fluid to be emitted from the nozzle orifice as an oscillating stream to more effectively cover a larger area of the glass to be cleaned.