CHECK VALVE
DESCRIPTION
A single washer system check valve is standard
equipment on this model, and is installed in the
washer system plumbing (Fig. 4). The check valve is
integral to the washer plumbing fitting located on
the underside of the cowl top panel behind the rear
of the hood panel opening in the engine compart-
ment. The check valve consists of a molded plastic
body with three barbed hose nipples, one at the inlet
side of the valve body and two at the outlet side. The
check valve cannot be adjusted or repaired and, if
faulty or damaged, it must be replaced.
OPERATION
The check valve provides more than one function
in this application. It serves as a plumbing 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 dis-
pensed through the washer nozzles, because the
washer pump would have to refill the washer plumb-
ing 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 noz-
zles 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 valve by overriding
the spring pressure applied to it by a piston. With
the diaphragm unseated, washer fluid is allowed to
flow toward the two washer nozzles. When the
washer pump stops operating, the spring pressure on
the piston seats the diaphragm over the sump well in
the valve and fluid flow in either direction within the
washer plumbing is prevented. The check valve can-
not be adjusted or repaired and, if faulty or damaged,
it must be replaced.
REMOVAL
(1) Unlatch and open the hood panel.
(2) Disconnect the washer hoses from the three
barbed nipples of the check valve unit (Fig. 5).
(3) Remove the check valve unit from the under-
side of the cowl top panel.
INSTALLATION
(1) Position the check valve unit to the underside
of the cowl top panel (Fig. 5).
(2) Reconnect the three washer hoses to the
barbed nipples of the check valve unit.
(3) Close and latch the hood.
WASHER FLUID LEVEL
SWITCH
DESCRIPTION
The optional washer fluid level switch is a single
pole, single throw switch that is integral to a unique
version of the washer pump/motor unit, located rear-
ward facing side of the washer reservoir, which is
located in a dedicated hole on the top of the sump
area near the back of the windshield washer reser-
Fig. 4 Check Valve
1 - INLET NIPPLE
2 - CHECK VALVE
3 - OUTLET NIPPLE (2)
Fig. 5 Check Valve Remove/Install
1 - COWL HOOD SEAL
2 - CHECK VALVE
3 - HOSE TO WASHER NOZZLE (2)
4 - HOSE FROM WASHER PUMP
VA WIPERS/WASHERS 8R - 7