JAC Trucks. Manual - part 138
ate the vehicle until the engine
warms up fully.
荫 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.
荫 The ideal coolant temperature
for the engine operation is 75 to
90益 (167 to 194毅F).
If the coolant temperature remains
at around 100益(212毅F), the engine
is slightly overheated. With the ve鄄
hicle stationary, continue to run the
engine to cool it or shift into a low鄄
er speed gear to reduce the en鄄
gine load.
If the pointer passes beyond 110益
(230毅F ) and enters the red zone,
the engine is overheated. The wa鄄
ter 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 immedi鄄
ately. 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.
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CAUTION:
When adding coolant, pay at鄄
tention to the following points.
荫 Use city water as coolant.
Avoid the use of hard water
such as river water if possible.
荫 When the radiator cap is re鄄
moved, 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.
STARTING & OPERATING
CAUTION:
Avoid skipping the next lower
speed gear when shifting
down, as overrunning readily
occurs.
荫 Same ratio as the coolant in the
radiator should be added.
荫 Before going up a slope, shift
down to prevent placing undue
load on the engine and drive line.
When going up a slope, maintain a
vehicle speed near the maximum
torque of the engine.
荫 Use care to prevent the engine
from overrunning.
Overrunning often occurs when
going down a slope or shifting
down.
荫 Engine over running occurs when
the engine is made to turn beyond
the maximum speed by the tires. Un鄄
due load on the engine could cause
severe engine damage.
Prior to going down a slope
1. Use engine brake and exhaust
brake,
2. Do not overuse the service
brakes.
63
荫 If a large amount of cold wa鄄
ter is abruptly poured in an
overheated
engine,
cracks
might develop in the crankcase,
etc. Slowly add water, while
keeping the engine running.