Hitachi 120-3 class Operator's Manual page 225

Hydraulic excavator
Table of Contents

Advertisement

Air Bleeding Procedures
IMPORTANT: If the hydraulic pump is not filled with oil, it
will be damaged when the engine is started.
The machine is equipped with two main pumps. Bleed air
from these pumps after changing hydraulic oil.
1. Remove air bleed plugs (5) on each pumps.
2. Fill the pump with oil through air bleed plugs (5) port on
each pumps until oil flows out of air bleed plug (5) hole.
3. Temporarily tighten air bleed plugs (5) on each pumps,
start the engine and run at slow idle. Loosen one of air
bleed plugs (5) slightly until oil flows from plug port to
release trapped air completely. Tighten air bleed plug (5).
Repeat this step for the rest of plugs.
4. Purge air from the hydraulic system by running the en-
gines at slow idle and operating the control levers slowly
and smoothly for 15 minutes.
5. Position the machine as illustrated in the oil level check-
ing procedure.
6. Lower the bucket to the ground.
7. Turn the auto-idle switch off.
8. Stop the engines. Remove the key from the key switches.
9. Pull the pilot control shut-off lever to the LOCK position
10. Check the hydraulic oil tank gauge. Remove cover (2) to
add oil if necessary.
MAINTENANCE
7-33
5
ZX120-3 Class
5
ZX180-3, 200-3, 270-3, 330-3 Class
M175-07-005
M1U1-07-035

Advertisement

Table of Contents
loading

Table of Contents