Service Manual
HYDRO-GEAR TRANSAXLE
4 - 8 TimeCutter
Z Service Manual
13. After any service where control linkage was
disturbed or after purging procedures have been
performed, check the neutral adjustment. If the
neutral adjustment needs to be performed, refer to
“Neutral Adjustment” on page 4 - 9.
14. Reconnect the brake levers and check the brakes,
refer to “Brake Adjustment” on page 4 - 11.
15. Remove the jumper wire to the seat and
reconnect the seat switch (Figure 51).
Figure 51
mvc-133
16. Remove the jack stands. Operate the unit making
sure the unit and all the safety devices are
working properly.
Purging Procedures – Hydro-Gear
Transaxles
Due to the effects air has on efficiency in hydrostatic
drive applications, it is critical that it be purged from the
system.
These purge procedures 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 inefficiency because its compression and
expansion rate is higher than that of the oil normally
approved for use in hydrostatic drive systems.
The resulting symptoms in hydrostatic systems may
be:
1. Noisy operation.
2. Lack of power or drive after short term operation.
3. High operation temperature and excessive
expansion of “oil”, in the latter case, oil may
overflow.
The following procedures should be performed with the
vehicle wheels off the ground, 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 the air is completely purged from the
transaxles. When the transaxles move forward at
normal speed, purging is complete.
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