ENGINE COOLING 6B – 5
ENGINE COOLANT CHANGE
PROCEDURE
1. To change engine coolant, make sure that the
engine is cool.
WARNING:
When the coolant is heated to a high temperature,
be sure not to loosen or remove the radiator cap.
Otherwise you might get scalded by hot vapor or
boiling water. To open the radiator cap, put a piece
of thick cloth on the cap and loosen the cap slowly
to reduce the pressure once the coolant has
become cooler.
2. Open radiator cap and drain the cooling system by
loosening the drain valve on the radiator and on the
cylinder body.
NOTE: For best results it is suggested that the engine
cooling system be flushed at least once a year. It is
advisable to flush the interior of the cooling system
including the radiator before using anti-freeze
(ethylene-glycol based).
Replace damaged rubber hoses as the engine anti-
freeze coolant is liable to leak out even minor cracks.
Isuzu recommends using Isuzu genuine anti-freeze
(ethylene-glycol based) or equivalent, for the cooling
system and not add any inhibitors or additives.
CAUTION:
A failure to correctly fill the engine cooling system
in changing or topping off coolant may sometimes
cause the coolant to overflow from the filler neck
even before the engine and radiator are completely
full.
If the engine runs under this condition, shortage of
coolant may possibly result in engine overheating.
To avoid such trouble, the following precautions
should be taken in filling the system.
3. To refill engine coolant, pour coolant up to filler neck
using a filling hose which is smaller in outside
diameter than the filler neck. Otherwise air between
the filler neck and the filling hose will block entry,
preventing the system from completely filling up.
4. Keep a filling rate of 9 liter/min. or less. Filling over
this maximum rate may force air inside the engine
and radiator.
And also, the coolant overflow will increase, making
it difficult to determine whether or not the system is
completely full.
5. After filling the system full, pull out the filling hose
and check to see if air trapped in the system is
dislodged and the coolant level goes down. Should
the coolant level go down, repeat topping-off until
there is no more drop in the coolant level.
6. Directly after filling the radiator, fill the reservoir to
the maximum level.
7. Install and tighten radiator cap and start the engine.
After idling for 2 to 3 minutes, stop the engine and
reopen radiator cap. If the water level is lower,
replenish.WARNING:
When the coolant is heated to a high temperature,
be sure not to loosen or remove the radiator cap.
Otherwise you might get scalded by hot vapor or
boiling water. To open the radiator cap, put a piece
of thick cloth on the cap and loosen the cap slowly
to reduce the pressure once the coolant has
become cooler.
8. After tightening radiator cap, warm up the engine at
about 2,000 rpm.
Set heater adjustment to the highest temperature
position, and let the coolant circulate also into
heater water system.
9. Check to see the thermostat has opened by the
needle position of a water thermometer, conduct a
5-minute idle again and stop the engine.
10. When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant be found, check the
coolant system and reservoir tank hose for leakage.
11. Fill the coolant into the reservoir tank up to “MAX”
line.
6B – 6 ENGINE COOLING
REMOVAL
1. Drain coolant.
2. AC Generator Drive Belt
1) Loosen AC Generator mounting bolt, adjust
plate lock bolt, and remove the drive belt.
3. Cooling Fan Assembly
1) Remove lock nut and take out cooling fan
assembly with cooling fan clutch.
4. Water Pump Assembly
INSPECTION
Make necessary repair and parts replacement if
excessive wear or damage is found during inspection.
Should any of the following problems occur, the entire
water pump assembly must be replaced.
1) Cracks in the water pump body
2) Coolant leakage from the seal unit
3) Play or abnormal noise in the bearing
4) Cracks or corrosion in the impeller
INSTALLATION
1. Gasket
1) Set gasket to gear case.
2. Water Pump Assembly
1) Install water pump assembly, and tighten to
specified torque.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)3. Cooling Fan Assembly
1) Install cooling fan assembly, and tighten to
specified torque.
Torque: 8 Nꞏm (0.8 kgꞏm/5.8 lb ft)
4. AC Generator Drive Belt
1) Install AC Generator drive belt and adjust belt
tension.
Torque: 40 Nꞏm (4.1 kgꞏm/29.7 lb ft)
For ACG to bracket
20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
For ACG to adjust plate
5. Fill coolant to specified capacity.
12
Legend
(1) Fan Pulley
(2) Water Pump Assembly
030RW009
ON-VEHICLE SERVICE
WAT E R P U M P
ENGINE COOLING 6B – 7
THERMOSTAT
REMOVAL
1. Disconnect battery ground cable.
2. Drain coolant from the radiator and engine.
3. Thermostat housing
1) Remove mounting bolt and remove thermostat
housing together with radiator hose.
4. Gasket
5. Thermostat
INSPECTION
Make necessary repair and parts replacement if
excessive wear or damage is found during inspection.
Submerge the thermostat assembly in the water.
Place wooden blocks on the bottom of the water
container.
Do not heat the thermostat directly.
Gradually increase the water temperature. Stir the
water so that the entire water is the same temperature.
1) Make sure that valve begins to open at the
specified temperature.
Valve Opening Temperature: 85°C (185°F)
2) Make sure that valve opens fully at the specified
temperature.
Valve Full Open Temperature: 100°C (212°F)
1
2
3
4
Legend
(1) Bolt
(2) Thermostat Housing
(3) Thermostat
(4) Intake Manifold
035RW002
031RS003
ENGINE COOLING 6B – 9
RADIATOR
REMOVAL
1. Disconnect battery ground cable
2. Loosen drain plug to drain coolant.
3. Radiator Hose
1) Disconnect lower hose and upper hose from the
engine.
4. Fan Guide
1) Remove clips on both sides and the bottom lock.
5. Reservoir Tank Hose
1) Disconnect the hose from radiator.
6. Bracket
7. Radiator Assembly
1) Remove the radiator assembly upward by the
hoses taking care not to damage the radiator
core by the fan blade.
2) Remove rubber cushions on both sides of the
bottom.
INSPECTION
Radiator Cap
1) Measure the valve opening pressure with the
radiator cap tester. Replace the radiator cap if it
exceeds the standard.
Valve opening pressure: 93.2 – 122.7 kPa
(0.95 – 1.25 kg/cm
2/
13.5 – 17.8 psi)
Check the condition of the negative pressure valve in
the center of the valve seat side of the cap. If the valve
seat does not move smoothly due to rust or dust, clean
and replace the radiator cap.Radiator Core
1) Deformed radiator fins could reduce radiation
effects, resulting in overheating. Straighten the fins.
In such a case, take care not to damage the fin
roots.
2) Remove dust and other foreign materials.
Flushing the Radiator
1) Wash the inside of radiator and the coolant
passage with water and a neutral detergent.
Remove all scales and rust.
110RW017
110RS006
6B – 12 ENGINE COOLING
Torque:
For A.C. Generator fixing bolt
40 Nꞏm (4.1 kgꞏm/29.7 lb ft)
For Adjusting plate fixing bolt
24 Nꞏm (2.4 kgꞏm/17.4 lb ft)
For Adjusting plate lock bolt
19 Nꞏm (1.9 kgꞏm/13.7 lb ft)
2) Adjust the A/C compressor drive belt by tightening
the belt tensioner bolt.
Legend
(1) Crankshaft Pulley
(2) A.C. Generator Pulley
(3) Cooling Fan Pulley
(4) A/C Compressor Pulley
(5) Belt Tensioner Pulley
5
3
24
1
012RW110
6C – 14 ENGINE FUEL
HIGH PRESSURE OIL PUMP
REMOVAL
1. Disconnect battery ground cable.
2. Remove air cleaner cover and air duct
3. Intercooler assembly
Refer to “Intercooler” in this manual.
4. Remove high pressure oil pipe
5. Timing belt cover
Disconnect CMP sensor cable.
Remove CMP sensor bracket.
6. Tensioner
7. Timing Belt
8. Remove high pressure oil pump timing pulley
9. Remove crankshaft damper pulley
10. Remove timing gear case cover
11. Remove idle gear A
Before removing idle gear A, set two bolts to the
sub gear of idle gear A and turn it to align the teeth
of idle gear A main gear.
Then lock them by bolts as shown in the illustration.Legend
(1) Idle gear A sub gear
(2) Idle gear A main gear
(3) Bar
(4) Lock bolt
1
2
43
Legend
(1) O-Ring
(2) High Pressure Oil Pump Assembly
(3) Nut
(4) O-Ring
040RW007
4 1
2
3
014RW177
ENGINE FUEL 6C – 17
4. Remove lock bolt of idle gear A.
5. Install timing gear case cover.
Refer to “Timing gear” in this manual.
6. Install front plate.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
7. Install timing pulley of high pressure oil pump.
Torque: 10 Nꞏm (1.0 kgꞏm/7.2 lb ft)
8. Install timing belt and tighten timing belt tensioner
assembly.
Refer to “Cylinder head” in this manual.
Legend
(1) Align Mark
(2) Camshaft Pulley
(3) Timing Belt
(4) High Pressure Oil Pump Pulley
(5) Bolt
(6) Tensioner Assembly
(7) Tensioner Bolt
(8) Tensioner Spring
9. Install CMP sensor bracket.
Torque: 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
10. Connect CMP sensor cable.
11. Install timing belt cover.
Torque: 9 Nꞏm (0.9 kgꞏm/6.5 lb ft)
12. Fill with about 300 cc of engine oil from the high
pressure oil pipe installation port of the oil rail using
an oil filler.
If assembled without filling the oil rail with oil, the
time for engine starting will be longer.
13. Immediately install high pressure oil pipe and
tighten to specified torque.
NOTE:
1) Use new O-ring.
2) Clean O-ring groove and fitting surface of parts.
3) Apply engine oil to O-ring.
Torque: 80 Nꞏm (8.1 kgꞏm/57.9 lb ft)14. Install the crankshaft damper pulley with specified
torque.
Torque: 220 Nꞏm (22 kgꞏm/159 lb ft)
15. Install the intercooler assembly.
Refer to “Intercooler” in this manual.
16. Install air cleaner cover and air duct.
1
2
3
8
67
4 5
F06RW055
6C – 18 ENGINE FUEL
HIGH PRESSURE OIL PIPE INSTALLATION
1. Install the nipple filter
1) Wash thread of the nipple filter, remove engine
oil and foreign material and air blow it.
2) Install nipple filter to high pressure oil pump inlet
port, tighten to the specified torque.
Torque : 90 Nꞏm (9.2 kgꞏm/66.5 lb ft)
2. Install the edge filter.
1) Wash thread, O-ring groove and fitting surface
of edge filter, remove engine oil and foreign
materials.
2) Install edge filter to high pressure oil pump,
tighten edge filter to the specified torque.
Torque : 90 Nꞏm (9.2 kgꞏm/66.5 lb ft)
3. Install upper bracket to two way valve, tighten them
temporarily.
4. Install pipe A to two way valve, tighten pipe A
temporarily with union nut D.
5. Install two way valve assembly to cylinder block,
tighgten with union nut C temporarily.6. Install pipe B to two way valve, tighten union nut E
and union nut F temporarily.
7. Tighten upper bracket to specified torque.
Torque : 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
8. Tighten union nut in the following order, union nut
C, D, F, and E to the specified torque.
Torque : 80 Nꞏm (8.1 kgꞏm/57.9 lb ft)
9. Tighten lower bracket to the specified torque.
Torque : 20 Nꞏm (2.0 kgꞏm/14.5 lb ft)
NOTE:
1) Wash inside pipe, inside union nut and O-ring seal
surface to remove engine oil and foreign materials.
2) It is recommended to check and replace the edge
filter when overhauling the engine, or if it is broken
inside the engine.
1
2
3
5
6
8 9
7
104
Legend
(1) Union Nut F
(2) Pipe B
(3) Union Nut E
(4) Upper Bracket
(5) Union Nut D(6) Pipe A
(7) Union Nut C
(8) Lower Bracket
(9) To Oil Rail
(10) To High Pressure Oil Pump through Edge Filter
040RW015