engine ISUZU TF SERIES 2004 Workshop Manual

3B-24 POWER-ASSISTED STEERING SYSTEM

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. Needle bearing fitting
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.

Pressure Switch
Check the switch operation as follows:
With engine idling and A/C on, turn the steering wheel
fully to the left; compressor should interrupt and engine
idle speed will increase. Shut off A/C and again turn
steering fully to the left; engine idle will increase. I
f
system fails to function properly, disconnect connector
at the pressure switch and repeat system check while
testing continuity across disconnected SW connector.

Reassembly
1. Install oil seal to front housing. Be sure to discard
used oil seal, and always use new parts fo
r
installation.
CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing.
2. Install shaft assembly.
3. Install the vanes to roter with curved face in contact
with the inner wall of cam.
442RS005
4. Install rotor and vanes to cam.
5. Install pin to front housing.
6. Install two new O-rings to front housing. Be sure to
discard used O-ring.
7. Install side plate.
CAUTION: When installing side plate, be careful not
to damage its inner surface. Damaged side plate
may cause poor pump performance, pump seizure
or oil leakage.
8. Install pump cartridge assembly to front housing.
9. Install snap ring to shaft end.
10. Install rear housing with a new O-ring. Be sure to
discard used O-ring. Then install bolt and tighten it
to specified torque.
Torque: 22-26 N




m (2.2-2.7 kg




m/16-20 lb ft)
11. Install suction pipe with a new O-ring. Be sure to
discard used O-ring. Then install bolt and tighten it
to specified torque.
Torque: 7.8-12 N




m (0.8-1.2 kg




m/6-9 lb ft)
12. Install relief valve and spring.
13. Install connector with a new O-ring. Be sure to
discard used O-ring. Tighten the connector to
specified torque.
Torque: 49-69 N




m (5.0-7.0 kg




m/36-51 lb ft)
14. Install pressure switch assembly and tighten it to
specified torque.
Torque: 15-20 N




m (1.5-2.0 kg




m/11-14 lb ft)

3B-28 POWER-ASSISTED STEERING SYSTEM

Inspection and Repair
Make all necessary adjustments, repairs, and part
replacements if wear, damage, or other problems are
discovered during inspection.

Rotor
442RS002
Check that the groove in the vane is free from excessive
wear and that the vane slides smoothly. When par
t
replacement becomes necessary, the pump cartridge
should be replaced as a subassembly.

Vane
442RS003
Sliding faces of the vane should be free from wear.
(Particularly the curved face at the tip that 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 finge
r
nail.
The parts with minor scores may be reused after lapping
the face.

Relief 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 fitting face
must be free from damage and wear.

O-ring, Oil Seal, Snap 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.

Pressure Switch
Check the switch operation as follows:
With engine idling and A/C on, turn the steering wheel
fully to the left; compressor should interrupt and engine
idle speed will increase. Shut off A/C and again turn
steering fully to the left; engine idle will increase. I
f
system fails to function properly, disconnect connecto
r
at the pressure switch and repeat system check while
testing continuity across disconnected SW connector.

Reassembly
1. Install oil seal to front housing. Be sure to discard
used oil seal, and always use new parts fo
r
installation.
CAUTION: When installing the oil seal, be careful
not to damage the oil seal contacting surface of the
housing.
2. Install shaft assembly.

POWER-ASSISTED STEERING SYSTEM 3B-43

Combination Switch
Combination Switch and Associated Parts


This illustration is based on the RHD model.
RTW43BLF000601
Legend
(1) Steering Column Cover
(2) Steering Wheel
(3) Inflator Module or Horn Pad
(4) Combination Switch and SRS Coil Assembly
(5) Instrument Panel Lower Cover
(6) Driver Knee Bolster (reinforcement)


Removal
1. Turn the steering wheel so that the vehicle's wheels
are pointing straight ahead.
2. Turn the ignition switch to "LOCK".
3. Disconnect the battery "-" terminal cable, and wait a
t
least 5 minutes. (with SRS air bag)
4.
Disconnect the yellow 2-way SRS connector located
under the steering column. (with SRS air bag)
CAUTION: The wheels of the vehicle must be
straight ahead and the steering column in the
"LOCK" position before disconnecting the steering
wheel. Failure to do so will cause the coil assembly
to become uncentered which will cause damage to
the coil assembly. (with SRS air bag)
5. Remove the engine hood opening lever, then
remove instrument panel lower cover.
6. Remove the driver knee bolster (reinforcement).

POWER-ASSISTED STEERING SYSTEM 3B-47

6. Install the driver knee bolster assembly.
7. Install the steering lower cover and engine hood
opening lever.
8. Install the steering wheel and align the setting
marks.
Refer to the adjustment method in case a mark is
not attached in this section.
NOTE: Confirm SRS and Horn harness connector is
fixed by the steering wheel.
RTW33BSH000601
CAUTION: Never apply force to the steering wheel in
direction of the shaft by using a hammer or othe
r
impact tools in an attempt to remove the steering
wheel. The steering shaft is designed as an energy
absorbing unit.
9. Tighten the steering wheel fixing nut to the specified
torque.
Torque: 31 - 39 N




m (3.2 – 4.0 kg




m/23 - 29 lb ft)
10. Support the inflator module and carefully connec
t
the SRS connector and horn lead. (with SRS air
bag)
060R300010

11. Connect the horn leads at center of wheel. (without
SRS air bag)
NOTE: Horn leads is letting a bracket top pass.
(Plastic type steering wheel only)



RTW43BSH000301
12. Push the born pad area 1-4.
Tighten the born pad fixing screw to the specifed
torque (without SRS air bag)
Torque: 2 - 4 N





m (0.2 – 0.4 kg





m/17 - 35 lb ft)
NOTE: A horn pad is not struck at the time o
f
attachment.



RTW43BSH00040

3B-48 POWER-ASSISTED STEERING SYSTEM

13. Align the each snap stud of driver air bag to the hole
of steering wheel. (with SRS air bag)
060R300030
060R300020

14. Push the SRS air bag area1 and area2. At that time
confirm the audible noise of each stud. (with SRS ai
r
bag)
060R300036

15. Enable the SRS (Refer to "Enabling the SRS" in this
section). (with SRS air bag)
16. Install driver knee bolster (reinforcement).
17. Install instrument panel lower cover then Install the
engine hood opening lever.
18. Connect the SRS connector. (with SRS air bag)
19. Connect the battery "-" terminal cable. (with SRS ai
r
bag)
20. Turn the ignition switch to "ON" while watching
warning light and check the light should flash 7 times
and then go off. If lamp does not operate correctly,
refer to Restraints section.

3B-50 POWER-ASSISTED STEERING SYSTEM

CAUTION: The wheels of the vehicle must be
straight ahead and the steering column in the
"LOCK" position before disconnecting the steering
wheel. Failure to do so will cause the coil assembly
to become uncentered which will cause damage to
the coil assembly. (with SRS air bag)
5. Remove the engine hood opening lever and
steering lower cover.
6. Remove driver knee bolster (reinforcement).
7. Disable the SRS (Refer to "Disabling the SRS" in
this section). (with SRS air bag)
8. Check the both side hole of the steering cover. (with
SRS air bag)
060R300025
9. Check the position of the pins in a hole. Push the
pin in the direction of an arrow. (with SRS air bag)
060R300032

10. Push the four pins at 
5
6 mm bar. (with SRS ai
r
bag)
060R300031
11. Cancel the lock four pins. (with SRS air bag)
12. Loosen the horn pad fixing screw at the rear of the
steering wheel (without SRS air bag).
430R300009

POWER-ASSISTED STEERING SYSTEM 3B-53

825RS048
4. Install the driver knee bolster assembly.
5. Install the steering lower cover and engine hood
opening lever.
6. Install the steering wheel and align the setting marks.
Refer to the adjustment method in case a mark is no
t
attached in this section.
NOTE: Confirm SRS and Horn harness connector is
fixed by the steering wheel.
RTW33BSH000601

CAUTION: Never apply force to the steering wheel in
direction of the shaft by using a hammer or othe
r
impact tools in an attempt to remove the steering
wheel. The steering shaft is designed as an energy
absorbing unit.
7. Tighten the steering wheel fixing nut to the specified
torque.
Torque: 31 - 39 N





m (3.2 – 4.0 kg





m/23 - 29 lb ft)

8. Support inflator module and carefully connect the
SRS connector and horn lead, then install inflato
r
module. (with SRS air bag)
060R300010
9. Connect the horn leads at center of wheel. (without
SRS air bag)
NOTE: Horn leads is letting a bracket type pass.
(Plastic type steering wheel only)



RTW43BSH000301

3B-54 POWER-ASSISTED STEERING SYSTEM

10. Push the born pad area 1-4.
Tighten the born pad fixing screw to the specifed
torque (without SRS air bag)
Torque: 2 - 4 N




m (0.2 – 0.4 kg




m/17 - 35 lb ft)
NOTE: A horn pad is not struck at the time o
f
attachment.



RTW43BSH000401
11. Align the each snap stud of driver air bag to the hole
of steering wheel. (with SRS air bag)
060R300030

060R300020
12. Push the SRS air bag area1 and area2. At that time
confirm the audible noise of each stud. (with SRS ai
r
bag)
060R300036
13. Enable the SRS (Refer to "Enabling the SRS" in this
section). (with SRS air bag)
14. Install driver knee bolster (reinforcement).
15. Install instrument panel lower cover, then install the
engine hood opening lever.
16. Connect the yellow 2-way SRS connector located
under the steering column. (with SRS air bag)
17. Connect the battery "-" terminal cable. (with SRS ai
r
bag)

System Inspection (with SRS air bag)
Turn the ignition switch to "ON" while watching warning
light.
The light should flash 7 times and then go off. If lamp
does not operate correctly, refer to Restraints section.

3B-56 POWER-ASSISTED STEERING SYSTEM

CAUTION: The wheel of the vehicle must be straight
ahead and the steering column in the "LOCK"
position before disconnecting the steering column
from the steering gear. Failure to do so will cause
the SRS coil assembly to become uncentered which
will cause damage to the SRS coil assembly. (with
SRS air bag)
5. Remove the engine hood opening lever and
steering lower cover.
6. Remove the driver knee bolster (reinforcement).
7. Disable the SRS (Refer to "Disabling the SRS" in
this section). (with SRS air bag)
8. Check the both side hole of the steering cover. (with
SRS air bag)
060R300025
9. Check the position of the pins in a hole. Push the
pin in the direction of an arrow. (with SRS air bag)
060R300032

10. Push the four pins at 
5
6 mm bar. (with SRS ai
r
bag)
060R300031
11. Cancel the lock four pins. (with SRS air bag)
12. Loosen the horn pad fixing screw at the rear of the
steering wheel (without SRS air bag).
430R300009

3B-60 POWER-ASSISTED STEERING SYSTEM

9. Turn the SRS coil counter clockwise to full, return
about 3 turns and align the neutral mark. (with SRS
air bag)
CAUTION: When turning the SRS coil counte
r
clockwise to full, stop turning if resistance is felt.
Forced further turning may damage to the cable in
the SRS coil.
826RW014
10. When installing the steering column cover, be sure to
route each wire harness as illustrated so that the
harnesses do not catch any moving parts.
825RW017
Legend
(1) Steering Column Cover
(2) Starter Switch Harness
(3) Combination Switch Harness
(4) Inflator Module Harness

11. Install steering wheel and align the setting marks
made when removing.
Refer to the adjustment method in case a mark is
not attached in this section.
NOTE: Confirm SRS and Horn harness connector is
fixed by the steering wheel.
RTW33BSH000601

CAUTION: Never apply force to the steering wheel in
direction of the shaft by using a hammer or othe
r
impact tools in an attempt to remove the steering
wheel. The steering shaft is designed as an energy
absorbing unit.
12. Tighten the steering wheel fixing nut to the specified
torque.
Torque: 31 - 39 N




m (3.2 – 4.0 kg




m/23 - 29 lb ft)
13. Support the module and carefully connect the
module connector and horn lead, then install inflato
r
module.
NOTE: Pass the lead wire through the tabs on the
plastic cover (wire protector) of inflator to prevent lead
wire from being pinched.
14. Tighten bolts to specified torque.
Torque: 2 - 4 N




m (0.2 – 0.4 kg




m/17 - 35 lb in)
15. Install driver knee bolster (reinforcement).
16. Install instrument panel lower cover.
17. Install the engine hood opening lever.
18. Connect the yellow 2-way SRS connector and horn
lead located under the steering column.
19. Connect the battery "-" terminal cable. (with SRS ai
r
bag)