Service Manual

HYDROSTATIC DRIVE SYSTEM
5-5
Toro Timecutter SS/MX/ZS Service Manual
5
Tracking Adjustment 2013 Models
If the unit tracks or pulls to the RIGHT:
- Turn the LH adjustment nut 1 full turn CLOCK-
WISE. If more adjustment is needed, turn the
adjustment nut 1 full turn at a time.
If the unit tracks or pulls to the LEFT:
- Turn the RH adjustment nut 1 full turn CLOCK-
WISE. If more adjustment is needed, turn the
adjustment nut 1 full turn at a time.
(Fig. 052)
Fig. 052 PICT-1097
Purging Procedure
Due to the effects air has on efciency in hydrostatic
drive applications, it is critical that it be purged from the
system.
This purge procedure should be implemented any time
a hydrostatic system has been opened to facilitate
maintenance, any additional oil has been added to the
system, or a replacement transaxle has been installed.
Air creates inefciency because its compression and
expansion rate is higher than that of the oil in hydrostatic
drive systems.
The 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”; in the latter case, oil may
overow.
The following procedure should be performed with the
vehicle wheels off the ground and then repeated under
operating conditions.
1. With the bypass valve open (push position) and the
engine running, slowly move the directional controls
(forward/reverse levers) in both forward and reverse
directions 5 to 6 times; as air is purged from the
transaxles, the oil level will drop.
2. With the bypass valves in the closed position (run
position) and the engine running, slowly move the
directional control levers in both forward and reverse
directions 5 to 6 times.
3. It may be necessary to repeat steps 1 and 2 until
all air is completely purged from the transaxles.
When the transaxles move forward at normal speed,
purging is complete.