RAM 3500 Truck 2WD L6-5.9L DSL Turbo VIN C (2003)
Check Valve: Description and Operation
Fig.3 Check Valve
CHECK VALVE
A single washer system check valve is standard equipment on this model, and is installed in the washer system plumbing. The check valve is integral
to the washer nozzle plumbing wye fitting located in the cowl plenum area beneath the cowl plenum cover/grille panel near the base of the windshield.
The check valve consists of a molded plastic body with a raised arrowhead molded into its center section that indicates the direction of the flow
through the valve, and three barbed hose nipples formed in a wye configuration on the outside circumference of the center section of the valve body.
The check valve cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
The check valve provides more than one function in this application. It serves as a wye connector fitting between the engine compartment and washer
nozzle sections of the washer supply hose. It 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 from when the washer switch is actuated until washer fluid was dispensed through the washer 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.
Fig.4 Check Valve
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 valve by overriding the spring pressure applied to it by a piston. With the diaphragm unseated, washer fluid is
