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Jeep Liberty KJ. Manual - part 311

SPECIFICATIONS

WIPER & WASHER SYSTEMS

TORQUE SPECIFICATIONS

DESCRIPTION

N·m

Ft. Lbs.

In. Lbs.

Rear Wiper Motor Output

Shaft Mounting Nut

Rear Wiper Motor

Mounting Screws

Washer Reservoir

Mounting Screws

Front Wiper Arm Mounting

Nuts

Rear Wiper Arm Mounting

Nut

Rear Wiper Arm Park

Ramp Mounting Screw

Front Wiper Module

Mounting Screws

Front Wiper Module

Mounting Nuts

8R - 36

WIPERS/WASHERS - SERVICE INFORMATION

CHECK VALVE

DESCRIPTION

A single front washer system check valve (2) is stan-
dard equipment on this vehicle, and is installed in the
front washer system plumbing. The front check valve
is integral to the front washer nozzle plumbing wye fit-
ting located in the cowl plenum area beneath the cowl
plenum cover/grille panel near the base of the wind-
shield. The check valve consists of a molded plastic
body with a raised arrowhead (4) molded into its cen-
ter section that indicates the direction of the flow
through the valve, and three barbed hose nipples (1 &
3) formed in a wye configuration on the outside cir-
cumference of the center section of the valve body.

The front check valve cannot be adjusted or repaired and, if inoperative or damaged, it must be replaced.

OPERATION

The front check valve provides more than one function
in this application. It serves as a wye connector fitting
between the cowl grille panel and washer nozzle sec-
tions of the front washer supply hose. It prevents
washer fluid from draining out of the front washer sup-
ply hoses back to the washer reservoir. This drain-
back would result in a lengthy delay when the front
washer switch is actuated until washer fluid was dis-
pensed through the front washer nozzles, because the
washer pump would have to refill the front 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 (5) through the washer plumbing,
the fluid pressure unseats a diaphragm (3) from over a sump well within the valve by overriding the spring pressure
(1) applied to it by a piston (2). With the diaphragm unseated, washer fluid is allowed to flow toward the two washer
nozzles (4). 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.

WIPERS/WASHERS - SERVICE INFORMATION

8R - 37

REMOVAL

1. Unlatch and open the hood.

2. Remove both front wiper arms from the wiper piv-

ots. (Refer to 8 - ELECTRICAL/WIPERS/WASH-
ERS - FRONT/FRONT WIPER ARM - REMOVAL).

3. Remove the cowl plenum cover/grille panel from

over the cowl plenum. (Refer to 23 - BODY/EXTE-
RIOR/COWL GRILLE - REMOVAL).

4. From the underside of the cowl plenum cover/grille

panel (5), disconnect the cowl plenum (3) and
washer nozzle hoses (1 & 6) from the three barbed
nipples of the front check valve (2).

5. Remove the front check valve from the underside

of the cowl plenum cover/grille panel.

INSTALLATION

1. Position the front check valve (2) to the underside

of the cowl plenum cover/grille panel (5). Be certain
that the flow direction arrow molded into the front
check valve body is oriented towards the front
washer nozzles.

2. From the underside of the cowl plenum cover/grille

panel, reconnect the cowl plenum (3) and washer
nozzle hoses (1 & 6) to the three barbed nipples of
the front check valve.

3. Reinstall the cowl plenum cover/grille panel over

the cowl plenum. (Refer to 23 - BODY/EXTERIOR/
COWL GRILLE - INSTALLATION).

4. Reinstall both front wiper arms onto the wiper piv-

ots. (Refer to 8 - ELECTRICAL/FRONT WIPERS/
WASHERS/FRONT

WIPER

ARM

INSTALLATION).

5. Close and latch the hood.

8R - 38

WIPERS/WASHERS - SERVICE INFORMATION

REAR WIPER MOTOR

DESCRIPTION

The rear wiper motor is concealed within the tailgate,
below the rear flip-up glass opening and behind the
tailgate inner trim panel. The end of the motor output
shaft (4) that protrudes through the tailgate outer
panel to drive the rear wiper arm and blade is the only
visible component of the rear wiper motor. A rubber
gasket (5), a bezel, and a nut secure and seal the
motor output shaft to the tailgate outer panel. A
molded plastic nut cover snaps onto the bezel to con-
ceal the nut and improve appearance. An integral con-
nector receptacle (6) connects the rear wiper motor to
the vehicle electrical system through a dedicated take
out and connector of the tailgate wire harness. The
rear wiper motor consists of the following major
components:

•

Bracket (3) - The rear wiper motor bracket consists of a stamped steel mounting plate for the wiper motor that
is secured with screws through two rubber insulators to the tailgate inner panel.

•

Rear Wiper Module (7) - The rear wiper motor electronic controls are concealed beneath a molded plastic
cover and includes the rear wiper system electronic logic and rear wiper motor electronic controls.

•

Motor (8) - The permanent magnet rear wiper motor is secured with screws to the rear wiper motor bracket.
The wiper motor includes an integral transmission, and the motor output shaft.

The rear wiper motor cannot be adjusted or repaired. If any component of the motor is inoperative or damaged, the
entire rear wiper motor unit must be replaced. The motor output shaft gasket, bezel, nut, and nut cover are available
for individual service replacement.

OPERATION

The rear wiper motor receives non-switched battery current through a fuse in the Junction Block (JB) on a fused
B(+) circuit and is connected to ground at all times. The rear wiper motor operation is controlled by the vehicle
operator through battery current signal inputs received by the rear wiper motor electronic control module from the
rear wiper switch circuitry that is integral to the right (wiper) control stalk of the multi-function switch on the steering
column. The module also receives an external control input from the flip-up glass ajar switch sense circuit. If the
rear wiper module senses that the flip-up glass is ajar, it will not allow the rear wiper motor to operate.

The rear wiper module electronic control logic uses these inputs, its internal inputs, and its programming to provide
a continuous wipe mode, an intermittent wipe mode, a wipe-after-wash mode, and off-the-glass wiper blade parking.
The wiper blade cycling is controlled by the internal electronic controls of the module. The module controls current
flow to the wiper motor brushes and provides an electronic speed control that speeds the wiper blade near the
center of the glass, but slows the wiper blade during directional reversals at each end of the wipe pattern and during
wiper blade off-the-glass parking for quieter operation.

The wiper motor transmission converts the rotary output of the wiper motor to the back and forth wiping motion of
the rear wiper arm and blade on the rear flip-up glass. The rear wiper motor may be diagnosed using conventional
diagnostic tools and methods.

WIPERS/WASHERS - SERVICE INFORMATION

8R - 39

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