Purging Procedure - Husqvarna Z400 Series Service Manual

4
Figure 3-10
5. Remove hydraulic filter plug (3 or 4) and hydraulic
filter.
6. Drain hydraulic oil.
7. Install new filter and tighten to specification.
Specification
Hydraulic Filter Plug Torque 115–135 lb-in (13–15 N•m)
8. Add 1.5 US qt (1.42 L) of new hydraulic oil and check
level with dipstick.
9. Purge the transmission. See "Purging Procedure" on
page 3-7.

Purging Procedure

The purge procedures must be implemented if the
hydrostatic system has been opened for maintenance or
when more oil has been added to the system.
Due to the effects air has on the efficiency of hydrostatic
drive applications, it is critical to purge the system.
Resulting symptoms of air in hydrostatic systems may
be: noisy operations, lack of power or drive after short
term operation, high operation temperature and
shortened component life.
NOTICE
Before starting procedure, make sure the oil
tank is at the proper oil level.
The transmission has two closed-loop drive
systems. One drive system is for the left wheel
and the other drive system is for the right
wheel.
Z400 Series
3
HUS1041
3-7
2
Figure 3-11
1. Open the bypass linkages (1 and 2) (horizontal
position).
3
Figure 3-12
2. Raise drive wheels off the ground and support with
appropriate stands (3).
3. Start the engine and run at high idle.
4. Slowly run the control handles in forward and reverse
5 or 6 times.
5. Turn engine off.
6. Close the bypass linkages (vertical position).
7. Start the engine and run at high idle.
8. Slowly run the control handles in forward and reverse
5 or 6 times.
9. Stop engine and check hydraulic oil level.
NOTICE
It may be necessary to repeat steps 3 and 4 until
all the air is completely purged from the system.
When the hydraulic drive operates at normal
noise levels and moves smoothly in forward and
reverse at normal speeds, the hydraulic drive is
considered purged.
MAINTENANCE
1
HUS1041
HUS1042