Bleeding The Hydraulic System - Toro 74920 Operator's Manual

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Figure 59
1. Apply a thin coat of oil on the surface of the rubber
seal of each filter.
2. Turn the filter clockwise until rubber seal contacts
the filter adapter then tighten the filter an additional
3/4 to 1 full turn. Repeat for the other filter
3. Install the filter guards over each filter as previously
removed. Use the three screws to secure the filter
guards.
4. Verify the vent plugs are removed before adding the
oil.
5. Slowly pour the specified oil through expansion
reservoir until oil comes out of one of the vent plug
holes. Stop and install that vent plug. Torque the
plug to 180 in-lb (20.3 N-m).
6. Continue to add oil through the expansion reservoir
until oil comes out of the remaining vent plug hole
on the second transmission. Stop and install that
vent plug. Torque the plug to 180 in-lb (20.3 N-m).
7. Continue to add oil through the expansion reservoir
until it reaches the FULL COLD line on the
expansion reservoir. Proceed to the Bleeding the
Hydraulic System section.
Important: Failure to perform the Bleeding
the Hydraulic System procedure after changing
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G008748
hydraulic filters and oil can result in irreparable
damage to the transaxle drive system.

Bleeding the Hydraulic System

1. Raise the rear of machine up and support with jack
stands (or equivalent support) just high enough to
allow drive wheels to turn freely.
1. Jacking points
2. Enter the operator's position. Start engine and
move throttle control ahead to 1/2 throttle position.
Disengage parking brake.
A. Move the bypass levers into the pushing the
machine position; refer to the Pushing the
Machine by Hand section in Operation. With
the bypass valves open and the engine running,
slowly move the motion control levers in both
forward and reverse (5 or 6 times).
B. Move the bypass levers into the operating
the machine position. With the bypass valve
closed and the engine running, slowly move the
directional control in both forward and reverse
directions (5 to 6 times).
C. Stop the engine and check the oil level in the
expansion reservoir. Add the specified oil as
until it reaches the FULL COLD line on the
expansion reservoir.
3. Repeat step 2 until all the air is completely purged
from the system.
When the transaxle operates at normal noise levels
and moves smoothly forward and reverse at normal
speeds, then the transaxle is considered purged.
4. Check the oil level in the expansion reservoir one
last time. Add the specified oil as until it reaches
the FULL COLD line on the expansion reservoir
if necessary.
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Figure 60