Maintenance
Safety, Operation and Maintenance Manual - Aug 2012
5-55
SY115C9/135C/155H Crawler Hydraulic Excavator
5.8.2.11 Air in hydraulic system - purge
Always prepare your machine as required
and lock/tag it out before proceeding.
See
“Preparing the machine” on page 2-58 and
“Lock-out and tag-out” on page 2-60.
1. Purging air from the pump
1) Loosen air vent plug (1) and check for
oil leak.
2) If no oil leaks, disconnect drain hose
from hydraulic pump and add hydraulic
oil to hydraulic pump through drain port
(2).
Well secure the disconnected hose. To
prevent over
fl
ow, hose opening must be
higher than oil level in hydraulic tank.
3) Tighten the plug (1) and reconnect the
drain hose after purging the air.
Note:
If drain hose is reconnected before tightening
the plug (1), oil will squirt out of the plug (1).
If the pump is operated when it is not fully
fi
lled
with hydraulic oil, extra heat will be generated
and pump damage could result.
2. Starting the engine
See
“
Engine Starting
”
on page 4-22
.
After starting the engine run it at low speed
for 10 minutes before you perform any op-
eration.
3. Purging air from hydraulic cylinders
1) Run the engine at low idle speed.
Extend and retract oil cylinder 4-5 times.
Note that the piston shall not reach its
Fig. 5-47
1
2
CZ135B-1104012
