1995 ISUZU TROOPER Workshop Manual

TOE-IN ADJUSTMENT
1. To adjust the toe-in angle, loosen the lock nuts on
the outer track rods and turn the outer track rods.
Turn both rods the same amount, to keep the
steering
wheel centered (Fig. 3A-1 0).
WHEEL ALIGNMENT SPECIFICATIONS
Toe-in mm (in) I 0 ± 2 (0 ± 0.08)
2. Tighten the lock nut to the specified torque.
~~~ Torque N·m (lb·ft) 118 (87)
Outer track rod
Lock nut
Fig. 3A-10
MAXIMUM STEERING ANGLE
ADJUSTMENT
The maximum steering angle of the front wheels can
be adjusted
with the stopper bolts under the frame side
members (Fig. 3A-11 ).
1. Position each front wheel on the turning radius
gauge in a straight-ahead position.
2. Set the parking brake firmly.
3. Adjust the inside wheel angle of each side with the
stopper
bolts.
NOTE: • The maximum protruding length (L) of
stopper bolt from the lock nut should be
10 mm or less (Fig. 3A-12)
4. Similarly adjust the inside wheel angle of the other
side
with stopper bolt.
WHEEL ALIGNMENT SPECIFICATION
Inside wheel
34° ~~:
Outside wheel 32°
NOTE:
Maximum steering angles should be set after adjusting
front wheel alignment.
FRONT END ALIGNMENT 3A-5
5. If the stopper between the lower link end and the
knuckle comes ahead of the stopper bolt (Fig. 3A-
13), adjust the stopper
bolt so that inner stopper
bolt touches the drop arm (relay lever).
6. Tighten the lock nut to the specified torque.
~~~ Torque N·m (lb·ft) 23 (17)
Fig. 3A-11
L
Stopper bolt Lock nut
Fig. 3A-12
Stopper
Fig. 3A-13

3A-6 FRONT END ALIGNMENT
MAIN DATE AND SPECIFICATION
GENERAL SPECIFICATION
Caster
Camber
King pin inclination
Toe-in
Max. steering
angle
TORQUE SPECIFICATION
mm (in)
(inside)
(outside)
2° 10' ± 45'(LWB) 2° ± 45' (SWB)
oo ± 30'
12° 30' ± 30'
0 ± 2 (0 ± 0.08)
34° ~~:
32°
1152 (112)~ ~1
,I~
Fig. 3A-14
N·m (lb·ft)

POWER STEERING GEAR AND PUMP 381 -1
SECTION 381
POWER STEERING GEAR AND PUMP
w CAUTION:
When fasteners are removed, always reinstall them at the same location from which they were removed.
If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct
part
number fastener is not available, a fastener of equal size and strength (or stronger) may be used.
Fasteners
that are not reused, and those requiring thread locking compound, will be called out. The correct
torque value must be used when installing fasteners that require it. If the above conditions are not
followed, parts or system damage could result.
CONTENTS
General Description ............................ 3B1- 1
Steering Wheel Free Play Adjustment .... 3B1-5
Power Steering
Gear........................ 3B1-1
Steering Gear ................................ 3B1-6
Hydraulic Pump .............................. 3B1- 1
Power Steering Pump ...................... 3B1-8
Pressure Switch
............................. 3B1-1
Unit Repair ...................................... 3B1- 9
Power Steering System Test
................. 3B1-3
Steering Gear ................................ 3B1-9
On-Vehicle Service ............................. 3B1- 4
Power Steering Pump ...................... 3B1-14
Maintenance
................................. 3B1- 4
Main Data and Specifications ................ 3B1-17
Fluid Level .................................... 3B1- 4 General Specifications ...................... 3B1-17
Bleeding The Power Steering System .... 3B1-4
Torque Specifications ....................... 3B1-17
Bleeding Procedure ......................... 3B1-4 Special Tools.................................... 3B1-18
Flushing The Power Steering System .... 3B1-4
GENERAL DESCRIPTION
The hydraulic power steering system consists of a
pump, an oil reservoir, a steering gear, a pressure
hose and a return hose.
POWER STEERING GEAR
The power steering gear has a recirculating ball
system which acts as a rolling thread between the
worm shaft and the rack piston. When the worm shaft
is
turned right, the rack piston moves up in gear.
Turning the worm shaft left moves the rack piston
down in gear. The rack piston teeth mesh with the
sector, which is part ofthe sector shaft.
Turning the worm shaft turns the sector shaft, which
turns the wheels through the steering linkage.
The control valve in the steering gear directs the
power steering fluid to either side of the rack piston.
The rack
piston converts the hydraulic pressure into
a mechanical force. If the steering system becomes
damaged and loses hydraulic pressure, the vehicle
can be controlled manually (Fig. 381-1).
HYDRAULIC PUMP
The hydraulic pump is vane-type design. The
submerged pump has housing and internal parts that
are inside the reservoir and operate submerged in oil.
There are two bore openings at the rear of the pump
housing. The larger opening contains the cam ring,
pressure
plate, thrust plate, rotor and vane assembly,
and end plate. The smaller opening contains the
pressure
line union, flow control valve and spring
(Fig. 381-2).
PRESSURE SWITCH
When hydraulic pressure reaches 3920 ± 690 kPa
(570 ± 100 psi), the pressure switch closes causing
Engine
Control Module (ECM) to actuate the idle air
control valve to prevent the overload-induced engine
speed down. The switch opens
when hydraulic
pressure drops to 2970 ± 560 kPa (430 ± 80 psi).

381-2 POWER STEERING GEAR AND PUMP
Fig. 381-1
II
Fig. 381-2
•

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 (Fig. 3B1-3).
The gage
must be between the shutoff valve and
pump.
Open the shutoff valve.
li5\l Tester: J-29877-A
~ Adapter: J-39213
3. Check the fluid level. Fill the reservoir with power
steering fluid, to the "Full" mark. Start the engine
and,
momentarily holding steering wheel against
stop, check the connections at tester
for leakage.
4. Bleed the system. Refer to "Bleeding the Power
Steering
System".
POWER STEERING GEAR AND PUMP 381-3
5. Start the engine and check the pump fluid level.
And power steering fluid if required. When the
engine is at
normal operating temperature,
increase engine speed to 1500 rpm.
U7 CAUTION:
VI 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), the pump is functioning
within its specifications.
• If the pressure recorded is higher than 9800 kPa
(1420 psi), the valve in the pump is defective.
• If the pressure recorded is lower than 9300 kPa
(1350 psi), the valve or the rotating group in the
pump is defective.
7. If the pump checks 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
ofthe gear, the 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.
Shut off Valve
J-29877-A
Oil Pressure Gauge
J-29877-A
Fig. 3B1-3