Hydraulic System Air Purge - Encore EDGE EE48FR691V32SS Operator's Manual

CAUTION
Raising the mower for service or
maintenance relying solely on
mechanical or hydraulic jacks could be
dangerous. The mechanical or hydraulic
jacks may not be enough support or
may malfunction allowing the unit to fall,
which could cause injury.
Do not rely solely on mechanical or
hydraulic jacks for support. Use
adequate jack stands or equivalent
support.

HYDRAULIC SYSTEM AIR PURGE

Service Interval: As Required
Due to the effects air has on efficiency in
hydrostatic drive applications, it is critical that
air is removed or purged from the system.
These purge procedures must be performed
anytime a hydrostatic system has been opened
for maintenance or repair, or if any additional oil
has been added to the system.
Air creates inefficiency because it has
compression and expansion rates that are
higher than that of oil.
Air trapped in the oil may cause the following
symptoms:
•
Noisy operation.
•
Lack of power or drive after short-term
operation.
•
High operation temperature and excessive
expansion of oil.
Before starting make sure the reservoir is at the
proper oil level. If it is not, fill to the vehicle
manufacturer's specifications.
The following procedures should be performed
with the vehicle drive wheels off the ground,
then repeated under normal operating
conditions.
WARNING
POTENTIAL FOR SERIOUS INJURY
Certain procedures required the vehicle
engine to be operated and the vehicle to be
raised off of the ground. To prevent
possible injury to the servicing technician
and/or bystanders, insure the vehicle is
properly secured.
1. With the bypass valve open, (see Drive
Wheel Release in the Operation section)
and the engine running, slowly move the
directional control in both forward and
reverse directions (5 to 6 times). As air is
purged from the unit, the oil level in the
reservoir will drop.
2. With the bypass valve closed and the
engine running, slowly move the directional
control in both forward and reverse
directions (5 to 6 times). Check the oil level,
and add oil as required after stopping
engine.
3. It may be necessary to repeat steps 1 and 2
until all the air is completely purged from the
system. When the drive wheels rotate
forward and reverse at normal speed and
the reservoir oil remains at a constant level,
purging is complete.
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