radiator cap ISUZU TROOPER 1998 Service Owner's Guide

ENGINE COOLING 6B – 3
WATER PUMP
The coolant pump is a centrifugal impeller type and is
driven by V type drive belt.
Legend
(1) Roller Bearing
(2) Ball Bearing
(3) Seal Unit
THERMOSTAT
The thermostat is a wax pellet type with a jiggle valve
and is installed in the thermostat housing.
Legend
(1) Bolt
(2) Thermostat Housing
(3) Thermostat
(4) Intake Manifold
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.
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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.

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.
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6B – 10 ENGINE COOLING
Checking for Coolant Leakage
1) Check the cooling system for leakage with the
radiator cap tester by applying 196.0 kPa (28.4 psi)
air pressure from filler neck to inside the radiator.
INSTALLATION
1. Radiator Assembly
1) Install rubber cushions on both sides of radiator
bottom.
2) Install radiator assembly with hose, taking care
not to damage the radiator core by a fan blade.
2. Bracket
1) Support the radiator upper tank with the bracket
and fix the radiator.
3. Reserve Tank Hose
4. Fan Guide, Lower
5. Radiator Hose
1) Connect inlet hose and outlet hose to the
engine.
2) Connect battery ground cable.
3) Pour coolant up to filler neck of radiator, and up
to MAX mark of reserve tank.
4) Start engine to warm up, and check for coolant
level. Replenish coolant if it does not reach the
radiator filler neck, and tighten the cap
completely.
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