Transmission Purging - Husqvarna MZ 61 Operator's Manual

Transmission Purging

Due to the effects air has on efficiency in hydrostatic drive
applications, it is critical to purge the system.
These purge procedures should be implemented any time a
hydrostatic system has been opened for maintenance or if any
additional oil has been added to the system.
Resulting symptoms in hydrostatic systems may be:
• Noisy operation.
• Lack of power or drive after short term operation.
• High operation temperature and excessive expansion of oil.
• Shortened component life.
Before starting, make sure the oil tank is at the proper oil level.
If not, fill to the specifications outlined previously.
The following procedures are best performed with the vehicle
drive wheels off the ground, then repeated under normal
operating conditions.
See Moving Machine By Hand in the Operation section for
bypass linkage adjustments.
1. Disengage the brake, if activated.
2. With the bypass linkage disengaged and the engine
running at fast idle, slowly move the directional control in
both forward and reverse directions five or six times. As air
is purged from the unit, the oil level will drop.
3. With the bypass linkage engaged and the engine running,
slowly move the directional control in both forward and
reverse directions five or six times. Check the oil level and
add oil as required after stopping the engine.
4. It may be necessary to repeat Steps 2 and 3 until all
the air is completely purged from the system. When the
hydraulic drive operates at normal noise levels and moves
smoothly forward and reverse at normal speeds, the
hydraulic drive is considered purged.
5. After the vehicle has been used two times, the oil level
should be checked while the oil is cold and adjusted
accordingly.
LUBRICATION
30