Bleeding The Hydraulic System - Toro 74179 Operator's Manual

3. Place a drain pan under the filter, remove the old filter,
and wipe the filter adapter gasket surface clean
(Fig. 45).
Figure 45
1. Hydraulic filter
4. Apply a thin coat of hydro fluid to the rubber gasket on
the replacement filter (Fig. 46).
5. Install the replacement hydraulic filter onto the filter
adapter. Do not tighten.
6. Remove the plastic bag from the tank opening and
allow the filter to fill with hydro fluid.
7. When fluid overflows the filter, turn the oil filter
clockwise until the rubber gasket contacts the filter
adapter; then tighten the filter an additional 1/2 turn
(Fig. 46).
8. If there is no fluid, add fluid to the reservoir to
approximately 1/4 in. (6 mm) below the top of the
baffle.
1
Figure 46
1. Hydraulic filter
2. Gasket
9. Clean up any spilled fluid.
1
m–4117
3
2
m–1256
3. Adapter
36
10. Start the engine and let it run for about two minutes to
purge air from the system. Stop the engine and check
for leaks. If one or both wheels will not drive, refer
Bleeding the Hydraulic System, page 36.
11. Check the fluid level in the hydraulic tank while the
fluid is warm. Add fluid to raise the level to the top of
the baffle, if required. Do not overfill.

Bleeding the Hydraulic System

The traction system is self bleeding; however, it may be
necessary to bleed the system if the fluid is changed or after
work is performed on the system.
1. Raise the rear of the machine so that the wheels are off
of the ground and support it with jack stands.
2. Start the engine and run it at idle speed. Engage the
traction on one side and spin the wheel by hand.
3. When the wheel begins to spin on its own, keep it
engaged until the wheel drives smoothly (minimum
2 minutes).
4. Check the hydraulic fluid level as it drops and add as
required to maintain the proper level.
5. Repeat this procedure on the opposite wheel.
Checking the Hydraulic Lines
After every 100 operating hours, check the hydraulic lines
and hoses for leaks, loose fittings, kinked lines, loose
mounting supports, wear, weather and chemical
deterioration. Make necessary repairs before operating.
Note: Keep the areas around the hydraulic system clean
from grass and debris buildup.
Warning
Hydraulic fluid escaping under pressure can
penetrate skin and cause injury.
If hydraulic fluid is injected into the skin it must
be surgically removed within a few hours by a
doctor familiar with this type of injury.
Gangrene may result if this is not done.
Keep body and hands away from pin hole leaks
or nozzles that eject high pressure hydraulic
fluid.
Use cardboard or paper to find hydraulic leaks.
Safely relieve all pressure in the hydraulic
system before performing any work on the
hydraulic system.
Make sure all hydraulic fluid hoses and lines are
in good condition and all hydraulic connections
and fittings are tight before applying pressure to
hydraulic system.