105
gine is overheated. The water temperature warning light will also light. Stop the
vehicle and run the engine at a slightly higher speed than the idle speed to
cool the engine.
Do not stop the engine immediately. A sudden rise in coolant temperature
could cause seizure of the engine.
When the engine is being cooled, check for coolant leaks. After the coolant
temperature has fallen, check for Iow coolant level or loose or broken fan belt.
CAUTION:
When adding coolant, pay attention to the following points.
●
Use city water as coolant. Avoid the use of hard water such as river water if
possible.
●
When the radiator cap is removed, place a cloth over the cap, raise the
pressure release lever and slowly open the cap. If the cap is abruptly opened
while the coolant is still hot, the hot water might gush out and might cause
scalding.
●
If a large amount of cold water is abruptly poured in an overheated engine,
cracks might develop in the crankcase, etc. Slowly add water, while keeping
the engine running.
104
Oil pressure
If the oil press ure falls below 0.5 kgf/cm
2
(50 kPa) while the engine is idling,
the OIL PRESSURE pilot lamp will light and the buzzer will sound.
Stop the engine and check for oil leaks and level at once. If they are good, the
oil system is defective. Have the oil system checked by an authorized dealer.
●
The OIL PRESSURE pilot lamp also light when the oil filter is clogged. Be
sure to check the pressure gauge to confirm the oil pressure.
In severe cold weather the pilot lamp may continue to light for a while after
starting because of increased oil viscosity. Do not operate the vehicle until the
engine warms up fully.
●
Do not keep your foot on the clutch pedal during operation.
Use of the clutch in half-engaged position will not only result in loss of power
but will also reduce the life of the clutch.
●
The ideal coolant temperature for the engine operation is 75 to 90~C (167 to
194
°
F).
If the coolant temperature remains at around 100 ~C (212 ~F), the engine is
slightly overheated. With the vehicle stationary, continue to run the engine to
cool it or shift into a lower speed gear to reduce the engine load.
If the pointer passes beyond 110~C (230
°
F ) and enters the red zone, the en
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’
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JAC HEAVY DUTY TRUCK
