Hitachi EX27U Operator's Manual page 152

EX50u
NOTE: Before leaving the Hitachi Factory, the cooling
system is filled with a mixture of water and Hi-
tachi Genuine Long-Life Coolant.
As long as Hitachi Genuine Long-Life Coolant is
used, the service intervals between changing
the coolant is once every two years (in autumn),
or every 2000 hours, whichever comes first.
CAUTION: Do not loosen the radiator cap until
the system is cool. Loosen the cap slowly to the
stop. Release all pressure before removing the
cap.
1. Remove the radiator cap. Open drain cock (1) on the
radiator and drain cock (2) on the engine block to al-
low the coolant to drain completely.
2. Close drain cocks (1) and (2). Fill the radiator with tap
water and a radiator cleaner agent. Start the engine
and run it at a speed slightly higher than slow idle;
when the needle of the temperature gauge reaches
the white zone, run the engine for about ten more
minutes.
3. Stop the engine and open drain cock (1) on the ra-
diator to allow the coolant to drain completely. Flush
out the cooling system with tap water, until draining
water is clear. This helps remove rust and sediment.
4. Close drain cock (1) on the radiator. Fill the radiator
with tap water and an anti-rust agent or antifreeze at
the specified mixing ratio. When adding coolant, do
so slowly to avoid mixing air bubbles in the system.
5. Run the engine to sufficiently bleed the air from the
cooling system.
6. After adding coolant, operate the engine for several
minutes. Check the coolant level again, and add
coolant if necessary.
MAINTENANCE
7-48
1
M571-07-001
M571-07-017
2
M571-07-008