Removing The Transmission Unit - Stiga MPV 320W Workshop Manual

WORKSHOP MANUAL
MPV 320W / 520W
c) Bleeding the oil circuit
Because of the effects air has on the efficiency of the hydrostatic transmissions, it is essential to
bleed it from the system.
The air creates inefficiency because its rate of compression and expansion is higher than that of
oil recommended for use in hydrostatic transmission systems.
These bleeding procedures should be implemented every time a hydrostatic system has been
opened to facilitate maintenance or the oil has been replaced.
The symptoms resulting from the presence of air can be:
• Noisy operations.
• Loss of power or traction after a short operation time.
• High operating temperature and excessive expansion of oil.
Before starting check the oil level is correct. If it isn't, top up according to the specifications de-
scribed in point b) of this chapter
It is preferable to perform the following procedures with the machine drive wheels raised off the
ground.
Then, repeat the same operations under normal operating conditions. If this is not feasible, per-
form the procedure in an open area, keeping a distance from objects or persons.
1. Disengage the parking brake if engaged.
2. With the bypass valve open and the engine running, slowly move the drive pedal forward and
backward (5 or 6 times) ..
3. With the bypass valve closed and the engine running, slowly move the drive pedal forward and
back (5 - 6 times). Check the oil level and top up if necessary, after stopping the engine
4. You may need to repeat steps 2 and 3 until the air has been completely bled from the system.
The transmission unit is deemed bled when it runs with normal noise levels and moves back-
wards and forwards at standard speed.

5.1.7 Removing the transmission unit

• Lift the front part of the machine
• Remove the front wheels
• Remove the discharge chute
• Free the upper belt, following steps 1 to 4 of
the "Replacement and adjustment of the upper
belt" procedure
• Remove the protective bar (1), following steps 1
to 5 of the "Replacement and adjustment of the
lower belt" procedure
5 - TRANSMISSION - WHEELS - STEERING
[
[ 5.2.2].
[ 6.3.1].
[ 5.1.1].
[ 5.1.2].
Chapter
2.3.2].
EDITION
2017
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