ISUZU TROOPER 1998 Service Repair Manual

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 49
3. Cooling Fan Assembly
·Remove cooling fan asm fixing nuts, cooling fan
asm, fan pulley and center.
4. Radiator Assembly
·Remove bracket and radiator asm.
5. Air Cleaner Cover & Air Duct
6. Intercooler Assembly (4JG2 -T only)
·(Refer to Intercooler removal steps in this section)
7. P/S Pump Drive Belts
·Loosen P/S pump fixing bolts and adjusting bolt
and remove two drive belts.
8. P/S Pump Assembly
·Remove two fixing bolts (front side), a fixing nut
(rear side) and support P/S pump asm with oil
hoses by tying to body side.
9. Engine Ground Cable
·Disconnect ground cable from A/C compressor
bracket.
10. AC Generator Harness
·Disconnect B terminal and harness connector
from AC generator.
11. A/C Compressor Assembly
·Remove A/C compressor fixing bolt (rear under
side of compressor) by using a long extension bar
at under side of wheel arch.
·Disconnect magnetic clutch harness connector.
·Remove fixing bolts (upper and front lower side
of compressor) and set A/C compressor asm with
pipe lines on battery carrier.
12. Vacuum Hose: Vacuum Pump
·Disconnect vacuum hose from vacuum pump.
13. Starter Harness
·Disconnect B terminal and put cable harness close
to chassis side.
·Disconnect S terminal connector.
14. Engine Harness.
·Disconnect engine harness close to engine side.
15. Accelerater Cable
·Loosen locking nut at bracket and disconnect
accelerater cable from injection pump control
lever.
16. Fuel Hoses
·Disconnect fuel hoses from injection pump side
and take care not to spill fuel and enter dust.
17. Engine Ground Cable
·Disconnect ground cable from left rear side of
timing gear case.

6A2 Ð 50 4JG2-NA/4JG2-TURBO ENGINE
18. Vacuum Hose : Vacuum Tank
·Disconnect vacuum hose from vacuum pump
side.
19. Glow Plug Harness
20. Transmission Assembly
·Install special tools (engine hangers) in front right
and left rear sides of cylinder head.
·Front right side; use the ground cable fixing bolt
on A/C compressor bracket.
·Left rear side; fix hanger together with oil cooler
hose clip.
Engine hanger: 5-8840-2032-0
·Left engine carefully by using hoist.
21. Engine Mounting
·Remove fixing bolts (both left and right side)
using extension bar and box wrench at under side
of wheel arches.
22. Engine Assembly
·Install special tools (engine hangers) in left rear
and front right sides of cylinder head.
·Lift engine carefully by using hoist.
·Lift front part of engine higher than rear part of it.
·Take out engine asm taking care not to damage
full pipes, brake pipes and etc.
INSTALLATION
22. Engine Assembly
·Position engine mountings by using hoist.
21. Engine Mounting
·After all fixing bolts (left: two bolts, rights: two
bolts) were inserted to every holes, and engine
asm and tighten fixing bolts to the specified
torque.
40 (4.1/30)N·m(Kg·m/lb·ft)
20. Transmission Assembly
·Refer to transmission installation steps
in section 7.
19. Glow Plug Harness
18 Vacuum Hose: Vacuum Tank
17. Engine Ground Cable
16. Fuel Hose
15. Accelerator Cable
·Refer to accelerater cable installation steps in
section 6C.

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 51
14. Engine Harness.
13. Starter Harness
12. Vacuum Hose: Vacuum Pump
11. A/C Compressor Assembly
·Tighten temporarily fixing bolts (upper and front
lower sides of compressor).
·Tighten fixing bolt (rear under side of
compressor) to the specified torque by using
along extension bar and torque wrench at under
side of wheel arch.
·Tighten fixing bolts (front upper and lower sides
of compressor) to the specified torque.
40 (4.1/30)N·m(Kg·m/lb·ft)

6A2 Ð 52 4JG2-NA/4JG2-TURBO ENGINE
6. Intercooler Assembly (4JG2-T Only)
·Refer to intercooler installation steps in this
section.
5. Air Cleaner Cover & Duct
4. Radiator Assembly
·Install cushion rubber in under left and right part
of radiator and position radiator.
·Fix radiator by bracket.
3. Cooling Fan Assembly
·Install cooling fan asm and tighten fixing bolts to
the specified torque.
2. Fan Shroud
1. Radiator Hose
·Connect upper and lower hose to engine side.
·Pour coolant in to radiator.
·Install battery.
·Connect window washer hose.
10. A.C. Generator Harness
9. Engine Ground Cable
·Attached ground cable to A/C compressor bracket.
8. P/S Pump Assembly
·Install P/S pump asm in engine and tighten
temporarily fixing nut.
7. P/S Pump Drive Belt
·Install drive belts adjust belt tension by adjusting
bolt and tighten locking bolt to the specified
torque.
·Refer to ÒDrive Belt AdjustmentÓ in section 6B.
8 (0.8/69)N·m(Kg·m/lb·in)
40 (4.1/30)N·m(Kg·m/lb·ft)

ENGINE COOLING 6B Ð 1
SECTION 6B
ENGINE COOLING
CONTENTS
PAGE
General Description ..................................................................................................................... 6B- 1
On-Vehicle Service ....................................................................................................................... 6B- 5
Water Pump ............................................................................................................................. 6B- 5
Thermostat ............................................................................................................................... 6B- 7
Radiator .................................................................................................................................... 6B- 9
Drive Belt Adjustment ............................................................................................................ 6B-15
GENERAL DESCRIPTION

6B Ð 2 ENGINE COOLING

ENGINE COOLING 6B Ð 3
The cooling system is a pressurized coolant forced
circulation type which consists of water pump, thermostat
cooling fan, radiator and other components. The
circulating coolant cools the lubricating oil in the oil filter
and turbocharger.
WATER PUMP
The coolant pump is a centrifugal impeller type and is
driven by V type drive belt.
THERMOSTAT
The thermostat is a wax pellet type with a jiggle valve and
is installed in the thermostat housing.
RADIATOR
The radiator is a tube type with corrugated fins. In order
to raise the boiling point of coolant, the radiator is fitted
with a cap in which the valve is operated under the
pressure.

6B Ð 4 ENGINE COOLING
ANTI-FREEZE SOLUTION
·Relation between Mixing ratio and Freezing point
Freezing temperature of the engine coolant varies
with the ratio of anti-freeze solution in water.
Proper mixing ratio can be determined by refering to
the chart. Supplemental inhibitors or additives
claiming to increase cooling capability that have not
been specifically approved by Isuzu are not
recommended for addition to the cooling system.
·Calculation of mixing ratio
Mixing ratio
Note: Anti-freeze solution + Water = 8.6 lit
Total cooling system capacity.
=Anti-freeze solution (Lit/qt.)
Anti-freeze solution (Lit/
qt.) + Water (Lit/qt.)
In case of 6.8 lit total cooling system capacity
Mixing
ratio (%)Anti-freeze
solution:
lit. (imp. qt./U.S. qt)Water:
lit. (imp.qt/U.S. qt)
0
5
10
15
20
25
30
35
40
45
500
0.3
0.7
1.0
1.4
1.7
2.0
2.4
2.7
3.1
3.40
(0.26/0.32)
(0.62/0.74)
(0.88/0.93)
(1.23/1.48 )
(1.50/1.80)
(1.76/1.86)
(2.11/2.23)
(2.38/2.85)
(2.72/2.87)
(2.99/3.60)6.8
6.5
6.0
5.8
5.4
5.1
4.8
4.4
4.1
3.7
3.4
(5.98/7.19)
(5.71/6.87)
(5.28/6.34)
( 5.1/6.13)
( 4.75/5.7)
(4.49/5.39)
(4.22/5.04)
(3.87/4.65)
( 3.6/4.33)
(3.26/3.91)
(2.99/3.59)
·Mixing ratio
Check the specific gravity of engine coolant in the
cooling system in temperature ranges from 0¡ C to
50¡ C using a suction type hydrometer, then
determine the density of the coolant by refering to the
table at left.

ENGINE COOLING 6B Ð 5
ON-VEHICLE SERVICE
WATER PUMP
REMOVAL
Preparation
·Drain coolant.
1. P/S pump Drive Belts
·Loosen P/S pump mounting bolt, loosen adjust
bolts and remove the drive belts.
2. AC Generator Drive Belt
·Loosen AC Generator mounting bolt (bottom
side), adjust plate lock bolt, and remove the drive
belt.
3. Cooling Fan Assembly
·Remove lock nut and take out cooling fan
assembly, distance piece, and fan pulley.
4. Crankshaft Damper Pulley.
5. Gear Case Cover.
6. Water Pump Assembly
7. O-ring
INSPECTION
Make necessary repair and parts replacement if extreme
wear or damage is found during inspection. Should any
of the following problems occur, the entire water pump
assembly must be replaced.
·Cracks in the coolant pump body
·Coolant leakage from the seal unit
·Play or abnormal noise in the bearing
·Cracks or corrosion in the impeller

6B Ð 6 ENGINE COOLING
INSTALLATION
7. O-ring
·Set O-ring in water pump body groove.
6. Water Pump Assembly
·Install water pump assembly, and tighten to
specified torque.
20(2.0/14)N·m (Kg·m/lb.ft)
5. Gear Case Cover
·Install gear case cover, and tighten to specified
torque.
8(0.8/69)N·m (Kg·m/lb·in)
4. Crankshaft Damper Pulley
·Install crankshaft damper pulley, and tighten to
specified torque.
3. Cooling Fan Assembly
·Install fan pulley, distance piece, and cooling fan
assembly in this order on water pump, and tighten
to specified torque.
19(1.9/14)N·m (Kg·m/lb·ft)
2. AC Generator Drive Belt
·Install AC Generator drive belt and adjust belt
tension.
·(Refer to Drive Belt Adjustment in this Section).
1. P/S Pump Drive Belts
·Install P/S pump drive belts and adjust belt
tension.
·(Refer to Drive Belt Adjustment in this Section).8(0.8/69)N·m (Kg·m/lb·in)