2003 JEEP GRAND CHEROKEE engine pressure

(8) Start engine and let idle long enough to circu-
late power steering fluid through flow/pressure test
gauge.
(9) Shut off the engine and check the fluid level,
add fluid as necessary. Start engine again and let
idle.
(10) The initial pressure reading should be
345-552 kPa (50-80 psi). If pressure is higher inspect
the hoses for restrictions and repair as necessary.
(11) Increase the engine speed to 1500 RPM and
read the flow meter. The reading should be 2.4 - 2.8
GPM, if the reading is below this specification the
pump should be replaced.
CAUTION: This next step involves testing maximum
pump pressure output and flow control valve oper-
ation. Do not leave valve closed for more than three
seconds as the pump could be damaged.
(12) Close valve fully three times for three seconds
and record highest pressure indicated each time.All
three readings must be at pump relief pressure
specifications and within 345 kPa (50 psi) of
each other.
²Pressures above specifications but not within
345 kPa (50 psi) of each other, replace pump.
²Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
CAUTION: Do not force the pump to operate against
the stops for more than 2 to 4 seconds at a time
because, pump damage will result.
(13) Open the test valve and turn the steering
wheel to the extreme left and right positions against
the stops. Record the highest pressure reading at
each position. Compare readings to the pump specifi-
cations chart. If pressures readings are not within 50
psi. of each other, the gear is leaking internally and
must be repaired.
GEAR INLET SPECIFICATIONS 4.0L & 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.0L 9653 kPa (1400 psi)
1500 RPM 2.4 - 2.8
GPM
4.7L 9653 kPa (1450 psi)
PUMP MOTOR SPECIFICATIONS 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.7L 9653 kPa (1900 psi)1100 RPM 2.4-2.8
GPM Minium
@ 200 psi
DIAGNOSIS AND TESTING - 4.7L -
HYDRAULIC
The following procedures are used to test the oper-
ation of the power steering and hydraulic fan sys-
tems on the vehicle. This test will provide the gallons
per minute (GPM) or flow rate of the power steering
pump along with any maximum relief pressure. Per-
form test anytime a power steering system problem
is present. This test will determine if the power
steering pump, hydraulic fan, and power steering
gear are not functioning properly. It will also deter-
mine if the flow coming out of the hydraulic fan
motor is sufficient for the power steering gear. The
following pressure and flow test is performed using
the Power Steering Analyzer Tool kit 6815 (Fig. 2)
and Adapter kit 8630 (Fig. 3).
FLOW TEST - FLOW FROM POWER STEERING
PUMP
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect the pressure gauge hose from the
Power Steering Analyzer to Tube 8630-2.
(3) Connect Adapter 8630-3 to Power Steering
Analyzer test valve end.
(4) Disconnect the high pressure hose from the
power steering pump.
(5) Connect Tube 8630-2 to the pump hose fitting.
(6) Connect the power steering hose from the fan
motor to Adapter 8630-3.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circu-
late power steering fluid through the flow/pressure
test gauge.
(9) Shut off the engine and check the fluid level,
add fluid ass necessary. Start engine again and let
idle.
(10) The initial pressure reading should be 483 -
690 kPa (70 - 100 psi). If pressure is higher inspect
the hoses for restrictions and repair as necessary.
Fig. 3 4.7L HYDRAULIC POWER STEERING TEST
ADAPTERS
WJSTEERING 19 - 5
STEERING (Continued)

(11) Increase the engine speed to 1100 rpm and
read the flow meter. The reading should be 2.6 GPM
minimum, if the reading is below this specification,
the pump should be replaced.
FLOW AND PRESSURE TEST - FLOW FROM
HYDRAULIC FAN MOTOR TO STEERING GEAR
(should be done if necessary after the Pump flow
test)
(1) Connect the pressure gauge hose from the
Power Steering Analyzer to Fitting 8630-1.
(2) Connect Adapter 8630-4 to Power Steering
Analyzer test valve end.
(3) Disconnect the high pressure hose from the
power steering gear.
(4) Connect Fitting 8630-1 to the high pressure
hose.
(5) Connect Adapter 8630-4 to the power steering
gear.
(6) Open the test valve completely.
(7) Start engine and let idle long enough to circu-
late power steering fluid through the flow/pressure
test gauge.
(8) Shut off the engine and check the fluid level,
add fluid ass necessary. Start engine again and let
idle.
(9) The initial pressure reading should be 345-552
kPa (50-80 psi). If pressure is higher inspect the
hoses for restrictions and repair as necessary.(10) Increase the engine speed to 1500 RPM and
read the flow meter. The reading should be 2.4 - 2.8
GPM if the reading is below this specification the fan
should be replaced.
CAUTION: This next step involves testing maximum
fan motor steering relief pressure. Do not leave the
valve closed for more than three seconds.
(11) Close the valve fully three times for three sec-
onds and record highest pressures indicated each
time. All three readings must be at fan motor steer-
ing relief pressures.
(12) Open the test valve and turn the steering
wheel to the extreme left and right positions against
the stops. Record the highest pressure readings at
each position. If pressure readings are not within 50
psi from each other, the gear is leaking internally
and must be repaired.
PUMP MOTOR SPECIFICATIONS 4.7L
ENGINERELIEF
PRESSURE   50FLOW RATE
(GPM)
4.7L 9653 kPa (1900 psi)1100 RPM 2.4-2.8
GPM Minium
@ 200 psi
19 - 6 STEERINGWJ
STEERING (Continued)

GEAR
TABLE OF CONTENTS
page page
GEAR
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................16
INSTALLATION.........................16
ADJUSTMENTS
STEERING GEAR.....................18
SPECIFICATIONS
POWER STEERING GEAR..............18
SPECIAL TOOLS
POWER STEERING GEAR..............19
PITMAN SHAFT
REMOVAL.............................20INSTALLATION.........................20
PITMAN SHAFT BEARING
REMOVAL.............................22
INSTALLATION.........................22
PITMAN SHAFT SEAL
REMOVAL.............................22
INSTALLATION.........................23
RACK PISTON/VALVE ASSEMBLY
REMOVAL.............................23
INSTALLATION.........................25
STUB SHAFT HOUSING
REMOVAL.............................25
INSTALLATION.........................25
GEAR
DESCRIPTION
The power steering gear is a recirculating ball type
gear (Fig. 1) .
The following gear components can be serviced:
²Pitman Shaft and Cover
²Pitman Shaft Bearings
²Pitman Shaft Oil Seal/Dust Seal
²Stud Shaft Housing with Seal
²O-Rings and Teflon Rings
NOTE: If rack piston assembly is damaged the gear
must be replaced.
OPERATION
The gear acts as a rolling thread between the
worm shaft and rack piston. The worm shaft is sup-
ported by a thrust bearing at the lower end and a
bearing assembly at the upper end. When the worm
shaft is turned the rack piston moves. The rack pis-
ton teeth mesh with the pitman shaft. Turning the
worm shaft turns the pitman shaft, which turns the
steering linkage.
REMOVAL
(1) Place the front wheels in the straight ahead
position with the steering wheel centered and locked.
(2) Remove the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(3) Drain or siphon the power steering system.(4) Remove the pressure and return lines (Fig.
2)from the steering gear. Refer to hose removal in
this section.
(5) Remove the column coupler shaft bolt (Fig.
2)and remove the shaft from the gear.
(6) Raise and support the vehicle.
(7) Remove the left front wheel and tire assembly.
(8) Remove the pitman arm from gear with Puller
C-4150A.
(9) Remove the windshield washer reservoir,(Refer
to 8 - ELECTRICAL/WIPERS/WASHERS/WASHER
RESERVOIR - REMOVAL).
(10) Remove the steering gear mounting bolts.
Remove the steering gear out of the engine compart-
ment (Fig. 3).
INSTALLATION
(1) Position the steering gear on the frame rail and
install the bolts. Tighten the bolts to 108 N´m (80 ft.
lbs.) torque.
(2) Install the pitman arm and tighten nut to 251
N´m (185 ft. lbs.).
(3) Install windshield washer reservoir,(Refer to 8 -
ELECTRICAL/WIPERS/WASHERS/WASHER RES-
ERVOIR - INSTALLATION).
(4) Install the wheel and tire assembly.
(5) Remove the support and lower the vehicle.
(6) Install the pressure and return hoses to the
steering gear and tighten to 20-38 N´m (14-28 ft.
lbs.).
(7) Install the column coupler shaft.
(8) Install the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
19 - 16 GEARWJ

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION - 4.0L, 4.7L................32
OPERATION
OPERATION - 4.7L....................32
OPERATION - 4.0L....................32
DIAGNOSIS AND TESTING - PUMP LEAKAGE . 33
STANDARD PROCEDURE
STANDARD PROCEDURE - INITIAL
OPERATION - 4.0L....................33
STANDARD PROCEDURE - INITIAL
OPERATION - 4.7L....................33
REMOVAL
REMOVAL - 4.0L ENGINE...............34
REMOVAL - 4.7L ENGINE...............34
INSTALLATION
INSTALLATION - 4.0L ENGINE...........34
INSTALLATION - 4.7L ENGINE...........34
SPECIFICATIONS
TORQUE CHART......................35
SPECIAL TOOLS
POWER STEERING PUMP..............36
FLUID COOLER
DESCRIPTION.........................36
REMOVAL.............................36
INSTALLATION.........................37
HOSES - 4.0L
DESCRIPTION
DESCRIPTION - PRESSURE LINE........37
DESCRIPTION - RETURN LINE...........37
OPERATION
OPERATION - PRESSURE LINE..........37
OPERATION - RETURN LINE............37
REMOVAL.............................37
INSTALLATION.........................37
HOSES - 4.7L
DESCRIPTION
DESCRIPTION - 1/2º PRESSURE HOSE....38DESCRIPTION - 1/2º RETURN HOSE......38
DESCRIPTION - 3/8º PRESSURE HOSE....38
DESCRIPTION - 3/8º GEAR OUTLET HOSE . 38
DESCRIPTION - 3/8º RETURN HOSE......38
OPERATION
OPERATION - 1/2º PRESSURE HOSE......38
OPERATION - 1/2º RETURN HOSE........38
OPERATION - 3/8º PRESSURE HOSE......39
OPERATION - 3/8º GEAR OUTLET HOSE . . . 39
OPERATION - 3/8ºRETURN HOSE........39
REMOVAL
REMOVAL - 1/29PRESSURE HOSE.......39
REMOVAL - 1/29RETURN HOSE..........39
REMOVAL - 3/89PRESSURE HOSE.......39
REMOVAL - 3/89RETURN HOSE..........39
REMOVAL - 3/89GEAR OUTLET HOSE.....40
REMOVAL - INLET COOLER HOSE........40
REMOVAL - OUTLET COOLER HOSE......40
INSTALLATION
INSTALLATION - 1/29PRESSURE HOSE....40
INSTALLATION - 1/29RETURN HOSE......40
INSTALLATION - 3/89PRESSURE HOSE....41
INSTALLATION - 3/89RETURN HOSE......41
INSTALLATION - 3/89GEAR OUTLET HOSE . 41
INSTALLATION - INLET COOLER HOSE....41
INSTALLATION - OUTLET COOLER HOSE . . 41
PULLEY
DESCRIPTION
POWER STEERING PUMP PULLEY - 3.1L
DIESEL.............................41
REMOVAL.............................41
INSTALLATION.........................42
RESERVOIR
REMOVAL.............................42
INSTALLATION.........................42
WJPUMP 19 - 31

PUMP
DESCRIPTION - 4.0L, 4.7L
Hydraulic pressure for the power steering system
is provided by a belt driven power steering pump
(Fig. 1) and (Fig. 2). The pump shaft has a
pressed-on drive pulley that is belt driven by the
crankshaft pulley.
OPERATION
OPERATION - 4.7L
The power steering pump is a constant flow rate
and displacement, vane-type pump. The pump has
internal parts that operate submerged in fluid. The
flow control orifice and the pressure relief valve,
which limits the pump pressure, are internal to the
pump. The reservoir is attached to the pump body
with spring clips. The power steering pump is used
to drive the hydraulic engine cooling fan, which sep-
arates the flow to the fan gerotors and the power
steering gear. The power steering pump is connected
to the engine cooling fan by pressure and return
hoses and the pump is connected to the steering gear
via a return hose from the steering cooler (Fig. 2).NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.OPERATION - 4.0L
The power steering pump is a constant flow rate
and displacement, vane-type pump. The pump inter-
nal parts operate submerged in fluid. The flow con-
trol orifice is part of the high pressure line fitting.
The pressure relief valve inside the flow control valve
limits the pump pressure. The reservoir is attached
to the pump body with spring clips. The power steer-
ing pump is connected to the steering gear by the
pressure and return hoses (Fig. 1).
NOTE: Power steering pumps have different pres-
sure rates and are not interchangeable with other
pumps.
Fig. 1 Pump With Integral Reservoir
1 - CAP
2 - FLUID RESERVOIR (TYPICAL)
3 - HIGH-PRESSURE FITTING
4 - DRIVE PULLEY
5 - PUMP BODY
6 - RESERVOIR CLIP
Fig. 2 4.7L POWER STEERING PUMP
1 - PRESSURE HOSE QUICK CONNECT NUT
2 - CAP
3 - FLUID RESERVOIR
4 - LOW-PRESSURE RETURN FROM THE COOLER
5 - LOW-PRESSURE RETURN FROM THE HYDRAULIC FAN
DRIVE
6 - PUMP BODY
7 - HIGH PRESSURE FITTING
19 - 32 PUMPWJ

(11) While the vehicle is in park, use the DRB III
to activate the hydraulic fan to full fan operation and
briefly rev the engine up to 3000 rpm to fully engage
the hydraulic fan.
(12) Check the fluid level add if necessary.
REMOVAL
REMOVAL - 4.0L ENGINE
(1) Remove serpentine drive belt,(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(2) Remove pressure and return hoses from pump
and drain the pump.
(3)
Loosen the pump bracket bolt at the engine block.
(4) Remove 3 pump mounting bolts (Fig. 4)
through pulley access holes.
(5) Tilt pump downward and remove from engine.
(6) Remove pulley from pump.
REMOVAL - 4.7L ENGINE
(1) Remove the serpentine drive belt,(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(2) Remove the pressure and return hoses from
pump and drain pump.
(3) Remove 3 pump mounting bolts through pulley
access holes (Fig. 5).
(4) Remove the pump from the vehicle.
INSTALLATION
INSTALLATION - 4.0L ENGINE
(1) Install pulley on pump.
(2) Install pump on the engine mounting bracket.
(3) Install 3 pump mounting bolts and tighten to
27 N´m (20 ft. lbs.).
(4) Tighten pump bracket bolt to 57 N´m (42 ft.
lbs.).
(5) Install the pressure line on the pump and
tighten to 28 N´m (21 ft. lbs.).
(6) Install the return hoses on pump.
(7) Install the drive belt,(Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
(8) Add power steering fluid,(Refer to 19 - STEER-
ING/PUMP - STANDARD PROCEDURE).
INSTALLATION - 4.7L ENGINE
(1) Position the pump on the left cylinder head
and install bolts through pulley access holes. Tighten
bolts to 28 N´m (21 ft. lbs.).
(2) Install the pressure and return hoses to pump.
(3) Install serpentine drive belt,(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(4) Add power steering fluid,(Refer to 19 - STEER-
ING/PUMP - STANDARD PROCEDURE).
Fig. 4 PUMP MOUNTING ± 4.0L
1 - PUMP ASSEMBLY
2 - PUMP BRACKET
Fig. 5 Pump Mounting
1 - LEFT CYLINDER HEAD
2 - PUMP
19 - 34 PUMPWJ
PUMP (Continued)

INSTALLATION
(1) Position and install the power steering cooler
to the vehicle.
(2) Install the three mounting bracket bolts (Fig.
6).
(3) Reconnect the upper hose at cooler (Fig. 6).
(4) Reconnect the lower hose at cooler (Fig. 6).
(5) Connect negative battery cable to battery.
(6) Refill the power steering fluid and bleed the
system,(Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE).
(7) Start engine and check for leaks.
(8) Install the grille opening reinforcement panel
(9) Install the front fascia grille,(Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT FASCIA
- INSTALLATION).
HOSES - 4.0L
DESCRIPTION
DESCRIPTION - PRESSURE LINE
The hose consists of two metal ends and rubber
center section that contains a tuning cable. The
pump end uses a quick connect fitting. Lubircation
must be used on the quick connect nut and o-ring
when installing.
DESCRIPTION - RETURN LINE
Power steering return line is a hose which is
clamped at the pump and the gear.
OPERATION
OPERATION - PRESSURE LINE
Power steering pressure line, is used to transfer
high pressure power steering fluid, from the power
steering pump to the power steering gear on the
4.0L. The 4.7L power steering pressure line, is used
to transfer high pressure power steering fluid, from
the power steering pump to the engine cooling fan
and the steering gear.
OPERATION - RETURN LINE
Power steering return line, is used to transfer low
pressure power steering fluid, from the power steer-
ing gear to the power steering pump.
REMOVAL
(1) Drain the power steering fluid from the reser-
voir.
(2) Remove the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
REMOVAL).
(3) Disconnect the power steering pressure hose
from the power steering pump and then the power
steering gear (Fig. 7).
(4) Disconnect the power steering return hose from
the power steering cooler and the reservoir.
(5) Remove the hoses from the vehicle.
INSTALLATION
(1) Install the hoses to the vehicle.
(2) Reconnect the power steering return hose to
the power steering cooler and the reservoir.
(3) Reconnect the power steering pressure hose to
the power steering pump and then the power steer-
ing gear.
(4) Install the air box,(Refer to 9 - ENGINE/AIR
INTAKE SYSTEM/AIR CLEANER HOUSING -
INSTALLATION).
(5) Refill the power steering fluid and bleed the
system,(Refer to 19 - STEERING/PUMP - STAN-
DARD PROCEDURE).
Fig. 7 POWER STEERING HOSES
1 - RETURN HOSE
2 - HIGH PRESSURE HOSE
3 - STEERING GEAR
WJPUMP 19 - 37
FLUID COOLER (Continued)

HOSES - 4.7L
DESCRIPTION
DESCRIPTION - 1/2º PRESSURE HOSE
The hose consists of two metal ends and a rubber
center with quick connect nuts at both ends. The
hose connects the power steering pump to the
hydraulic fan motor and is clipped to the fan shroud
(Fig. 8). Lubrication must be used on the quick con-
nect nuts and o-rings when installing.
DESCRIPTION - 1/2º RETURN HOSE
The fan motor return line is a molded rubber hose
that is clamped at the hydraulic motor and the power
steering reservoir (Fig. 9).
DESCRIPTION - 3/8º PRESSURE HOSE
The hose consists of two metal ends and two rub-
ber sections one of which contains a tuning cable
(Fig. 10). The hose is clipped in two places to the fan
shroud. Lubrication must be used on the o-rings
when installing.
DESCRIPTION - 3/8º GEAR OUTLET HOSE
The gear outlet line consists of a metal section that
connects to the gear and a rubber section that clamps
to the steering cooler inlet tube (Fig. 11).
DESCRIPTION - 3/8º RETURN HOSE
The return hose is a formed rubber hose that con-
nects the steering cooler outlet tube to the power
steering reservoir (Fig. 12). It is clamped at both
ends.
OPERATION
OPERATION - 1/2º PRESSURE HOSE
The 1/2º pressure hose is used to transfer high
pressure power steering fluid from the power steer-
ing pump to the engine cooling fan motor (Fig. 8).
OPERATION - 1/2º RETURN HOSE
The power steering return line returns low pres-
sure excess flow from the hydraulic fan motor back to
the power steering pump (Fig. 9).
Fig. 8 1/2(PRESSURE HOSE
1 - 1/29PRESSURE HOSE
2 - POWER STEERING PUMP
3 - STEERING GEAR
Fig. 9 1/2(RETURN HOSE
1 - 1/29RETURN HOSE
2 - HOSE CLAMP
Fig. 10 3/8(PRESSURE HOSE
1 - 3/89PRESSURE HOSE
2 - STEERING GEAR
19 - 38 PUMPWJ