Hitachi ZX27U-2, Operator'S Manual

Page: 165 / 230

MAINTENANCE
7-45
Change Coolant
--- twice a years (in spring and autumn)
NOTE: In case genuine Hitachi Long-Life Coolant is
used, change the coolant every two years (in
autumn every other year), or every 2000 hours,
whichever comes first.
WARNING: Do not loosen the radiator cap unless
the system is cool. Hot steam may escape, pos-
sibly causing severe burns. Loosen the radiator
cap slowly to the stop after the coolant becomes
cool. Release all pressure before removing the
cap.
Procedure of Coolant Change
1. Remove the radiator cap. Open drain cock (1) on the
radiator and drain the drain valve on the water jacket
to allow the coolant to drain completely. Drain impuri-
ties such as water scale at the same time.
2. Close radiator drain cock (1) and the drain valve on
the water jacket. Fill the radiator with fresh water in-
cluding less impurity or normal tap water and a ra-
diator cleaner agent. Start the engine and run it at a
speed slightly higher than slow idle to raise the cool-
ant temperature until the needle of the temperature
gauge reaches the white zone. Then, run the engine
further for about ten minutes.
3. Stop the engine and open radiator drain cock (1) to
allow the coolant to drain. Flush out the cooling sys-
tem with fresh water including less impurity or normal
tap water, until draining water becomes clear. This
helps remove water scale.
4. Close radiator drain cock (1). Fill the radiator with
fresh water which includes fewer impurities or normal
tap water and LLC at the specified mixing ratio. When
adding coolant, do so slowly to avoid mixing air bub-
bles in the system. Run the engine to sufficiently
bleed the air from the cooling system.
5. After adding coolant, operate the engine for several
minutes. Check the coolant level again, and add
coolant if necessary.
M1M7-07-048
M1M7-07-049
M1M7-07-050
M1M7-07-051
1
1
ZX27U
-2
, ZX30U
-2
, ZX35U
-2
ZX40U
-2
, ZX50U
-2
ZX40U
-2
, ZX50U
-2
ZX27U
-2
, ZX30U
-2
, ZX35U
-2