power steering fluid ISUZU TROOPER 1998 Service User Guide

2A – 10 POWER STEERING
POWER STEERING SYSTEM TEST
TEST PROCEDURE
Test of fluid pressure in the power steering system
is performed to determine whether or not the oil
pump and power steering unit are functioning
normally.
The power steering system test is method used to
identify and isolate hydraulic circuit difficulties.
Prior to performing this test, the following
inspections and corrections, if necessary, must be
made.
INSPECT
•Pump reservoir for proper fluid level.
•Pump belt for proper tension.
•Pump driver pulley condition.
1. Place a container under the pump to catch the
fluid when disconnecting or connecting the
hoses.
2. With the engine NOT running , disconnect the
pressure hose at the power steering pump and
install Power Steering tester.
The gage must be between the shutoff valve
and pump. Open the shutoff valve.
Tester: 5-8840-0135-0 (J-29877-A)
Adapter: 5-8840-2297-0 (For 6VD1, 6VE1, 4JX1)
5-8840-0136-0 (For 4JG2)3. Check the fluid level. Fill the reservoir with
power steering fluid, to the “Full” mark. Start
the engine then turn the steering wheel and
momentarily hold it against a stop. Turn off
and check the connections at tester for leakage.
4. Bleed the system. Refer to “Bleeding the
Power Steering System” in this section.
5. Start the engine and check the pump fluid
level. Add power steering fluid if required.
When the engine is at normal operating
temperature, increase engine speed to 1500
rpm.
CAUTION:
Do not leave shutoff valve fully closed for more
than 5 seconds, as the pump could become
damaged internally.
6. Fully close the shutoff valve. Record the
highest pressures.
•If the pressure recorded is within 9300-9800
kPa (1350-1420 psi) For 6VD1, 6VE1, and
9800-10300 kPa (100-105 kg/cm
2/ 1420-1490
psi) For 4JG2, 4JX1, the pump is functioning
within its specifications.
•If the pressure recorded is higher than 9800
kPa (1420 psi) For 6VD1, 6VE1, and 10300
kPa (105 kg/cm
2/ 1490 psi) For 4JG2, 4JX1,
the valve in the pump is defective.

POWER STEERING 2A – 11
•If the pressure recorded is lower than 9300
kPa (1350 psi) For 6VD1, 6VE1, and 9800 kPa
(100 kg/cm
2/ 1420 psi) For 4JG2, 4JX1, the
valve or the rotating group in the pump is
defective.
7. If the pump pressure are within specifications,
leave the valve open and turn (or have
someone else turn) the steering wheel fully in
both directions. Record the highest pressures
and compare with the maximum pump
pressure recorded in step 6. If this pressure cannot be built in either (or one) side of the
power steering gear, the power steering gear is
leaking internally and must be disassembled
and repaired.
8. Shut the engine off, remove the testing gage,
reconnect the pressure hose, check the fluid
level and make the needed repairs.
9. If the problem still exists, the steering and front
suspension must be thoroughly examined.

BLEEDING THE POWER
STEERING SYSTEM
When a power steering pump or gear has been
installed, or an oil line has been disconnected, the
air that has entered the system must be bled out
before the vehicle is operated. If air is allowed to
remain in the power steering fluid system, noisy
and unsatisfactory operation of the system may
result.
BLEEDING PROCEDURE
When bleeding the system, and any time fluid is
added to the power steering system, be sure to use
only power steering fluid as specified in
“MAINTENANCE AND LUBRICATION” in section
0B.
1. Fill the pump fluid reservoir to the proper
level and let the fluid settle for at least two
minutes.
2. Start the engine and let it run for a few
seconds.
Do not turn the steering wheel. Then turn the
engine off.
3. Add fluid if necessary.
4. Repeat the above procedure until the fluid
level remains constant after running the
engine.
5. Raise the front end of the vehicle so that the
wheels are off the ground.
6. Start the engine. Slowly turn the steering
wheel right and left, lightly contacting the
wheel stops.
7. Add power steering fluid if necessary.
8. Bring down the vehicle, set the steering wheel
at the straight forward position after turning it
to its full steer positions 2 or 3 times, and stop
the engine.
9. Stop the engine. Check the fluid level and
refill as required.
10. If the fluid is extremely foamy, allow the
vehicle to stand a few minutes and repeat the
above procedure.
INSPECT
•Belt for tightness.
•Pulley for looseness or damage. The pulley
should not wobble with the engine running.
•Make sure that hose and pipes are properly
fitted.
•Fluid level and fill to the proper level.
FLUSHING THE POWER
STEERING SYSTEM
1. Raise the front end of the vehicle off the
ground until the wheels are free to turn.
2. Remove the fluid return line at the reservoir
inlet connector and plug the connector.
Position the line toward a large container to
catch the draining fluid.
3. While running the engine at idle, fill the
reservoir with new power steering fluid. Turn
the steering wheel in both directions. Do not
contact wheel stops or hold the wheel in a
corner, or fluid will stop and the pump will be
in pressure relief mode. A sudden overflow
from the reservoir may develop if the wheel is
held at a stop.
4. While refilling the reservoir, check the
draining fluid for contamination. If foreign
material is still evident, replace all lines,
disassemble and clean or replace the power
steering system components. Do not re-use
any drained power steering fluid.
5. Install all the lines and hoses. Fill the system
with new power steering fluid and bleed the
system as described in “Bleeding The Power
Steering System”. Operate the engine for
about 15 minutes. 2A – 12 POWER STEERING
ON-VEHICLE SERVICE

POWER STEERING 2A – 25
Seal Ring Setting
Note the setting direction. Always install a new part.
Apply a thin coat of power steering fluid to lip of each
part.
Dust Seal Setting
Note the setting direction. Always install a new part.
Apply a thin coat of power steering fluid to lip of each
part.
Gasket Setting
Note the setting direction. Always install a new part.
Apply a thin coat of power steering fluid to lip of each
part.

2A – 30 POWER STEERING
Vane
Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip in contact with the
cam should be free from wear and distortion).
When part replacement becomes necessary, the pump
cartridge should be replaced as a subassembly.
Cam
The inner face of the arm should have a uniform contact
pattern without a sign of step wear.
When part replacement becomes necessary, the pump
cartridge should be replaced as a subassembly.
Side plate
The sliding faces of parts must be free from step wear
(more than 0.01 mm), which can be felt by the finger nail.
The parts with minor scores may be reused after lapping
the face.
Valve
The sliding face of the valve must be free from burrs and
damage.
The parts with minor scores may be reused after
smoothing with emery cloth (#800 or finer).
Shaft
Oil seal sliding faces must be free from a step wear which
can be felt by the finger nail.
Bushing face must be free from damage and wear.
O-ring, oil seal, retaining ring
Be sure to discard used parts, and always use new parts
for installation. Prior to installation, lubricate all seals and
rings with power steering fluid.
REASSEMBLY
27. Rear Housing
26. Pin
25. Cam
24. Rotor and Vane
1. Install the rotor with its punch mark facing the front
housing.
2. Install the vanes with curved face in contact with
the inner wall of the cam.

6E±300
ENGINE DRIVEABILITY AND EMISSIONS
4. Disconnect the red, white, and blue electrical
connectors at the PCM.
5. Remove the two screws in the front of the PCM.
6. Remove the one screw at the left rear of the PCM.
7. Pull the PCM straight out from the dashboard.
TS23757
Installation Procedure
1. Insert the PCM into the dashboard.

Line up the holes in front for the mounting screws.
2. Install the PCM with two screws in the front and one
screw at the left rear.
3. Plug the red, white, and blue connectors into the
appropriate sockets.
TS23757
EEPROM
General Description
The Electronically Erasable Programmable Read Only
Memory (EEPROM) is a permanent memory that is
physically soldered within the PCM. The EEPROM
contains program and calibration information that the
PCM needs to control powertrain operation.
EEPROM Programming
1. Step-up ± Ensure that the following conditions have
been met:

The battery is fully charged.

The ignition is ªON.º

The Vehicle Interface Module cable connection at
the DLC is secure.
2. Program the PCM using the latest software matching
the vehicle. Refer to up-to-date Techline equipment
user's instructions.
3. If the PCM fails to program, Refer to
UBS 98 model
year Immobilizer Workshop Manual.
Functional Check
1. Perform the On-Board Diagnostic System Check.
2. Start the engine and run for one minute.
3. Scan for DTCs using the Tech 2.
Power Steering Pressure (PSP)
Switch
General Description
The Power Steering Pressure (PSP) switch closes when
the hydraulic pressure reaches 3920 + 690 kPa (570 +
100 psi). This causes the PCM to actuate the idle air
control valve in order to prevent the additional load from
slowing down the engine. The switch opens when the
hydraulic pressure drops to 2970 + 560 kPa (430 + 80
psi).
Removal Procedure
1. Disconnect the PSP switch pigtail from the wiring
harness.

The pigtail is permanently attached to the switch.
Do not attempt to remove the wires from the
sensor.

Have a container ready to catch the power steering
fluid that leaks out of the line when the switch is
removed.

6E±301 ENGINE DRIVEABILITY AND EMISSIONS
2. Remove the PSP switch from the power steering line.

Plug the line to prevent excessive loss of fluid and
possible contamination of the power steering
system.
TS23760
Installation Procedure
1. Install the PSP switch in the power steering line.
TS23760
2. Connect the PSP switch pigtail to the wiring harness.
3. Check the power steering fluid level. Refer to
Power
Steering
.
4. Start the engine. Watch the PSP switch for signs of
fluid leakage.
Throttle Position (TP) Sensor
Removal Procedure
1. Disconnect the negative battery cable.
2. Disconnect the TPS electrical connector.3. Remove the bolts and the TP sensor from the throttle
body.
TS23747
NOTE: Do not clean the TP sensor by soaking it in
solvent. The sensor will be damaged as a result.
Function Check
Use a Tech 2 to check the TP sensor output voltage at
closed throttle.

The voltage should be under 0.85 volt.

If the reading is greater than 0.85 volt, check the
throttle shaft to see if it is binding. Check that the
throttle cable is properly adjusted, also. Refer to
Throttle Cable Adjustment.

If the throttle shaft is not binding and the throttle cable
is properly adjusted, install a new TP sensor.
Installation Procedure
1. Install the TP sensor on the throttle body with the
bolts.
TS23747