Isuzu NHR 4J Series, Workshop Manual

Page: 46 / 406

00 – 42 SERVICE INFORMATION
NOTE:
For best result 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 to use lsuzu
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 up 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 of the filler neck.
Othewise 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 to the 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-up until
there is no more drop in the coolant level.
6 After directly 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 when 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 through the