Toro 74504TE, Operator'S Manual, Page: 49 / 64

Replacing the Hydraulic Fluid and
Filters
Service Interval: After the first 50 hours
Every 500 hours/Yearly (whichever comes
first)—Change the hydraulic filters and hydraulic fluid.
Change the hydraulic fluid more frequently in severe
conditions or in a hot operating climate. Contact your
Authorized Service Dealer for a hydraulic kit to replace the
hydraulic filters.
WARNING
Hot hydraulic fluid can cause severe burns.
Allow the hydraulic fluid to cool before performing
any maintenance on the hydraulic system.
1. Disengage the PTO and set the parking brake.
2. Shut off the engine and wait for all moving parts to
stop before leaving the operating position.
3. Remove the fuel tank; refer to Removing the Fuel Tank
(page 36) .
4. Remove the hydraulic-reservoir cap.
5. Place a drain pan under the drain plugs ( Figure 71 ).
Figure 71
1. Drain plug 2. Hydraulic filter
6. Remove the drain plugs.
7. Allow the hydraulic fluid to fully drain from the
machine.
8. Remove the hydraulic filter cap and filter from each
transmission.
9. Install new hydraulic filters with the spring side facing
out and install the filter caps.
10. Install the drain plugs.
11. Loosen the vent plug in each transmission so that it is
loose and wobbles (
Figure 72 ).
Note:
This allows air to escape the hydraulic system
as you add hydraulic fluid.
Figure 72
Left transmission shown
1. Vent plug
12. Slowly add fluid to the hydraulic tank until it starts to
come out 1 of the vent plugs.
Important:
Use the fluid specified in Servicing
the Hydraulic System (page 48) or equivalent.
Other fluids could cause system damage.
Important:
Monitor the level of fluid in the
hydraulic tank so that you do not overfill it.
13. Tighten the vent plugs.
14. Install the hydraulic-tank cap.
15. Install the fuel tank.
16. Start the engine and let it run for about 2 minutes to
purge air from the system.
17. Shut off the engine and check for leaks.
Note:
If 1 or both wheels do not drive, refer to
Bleeding the Hydraulic System (page 49) .
Bleeding the Hydraulic System
The traction system is self-bleeding, however, you may need
to bleed the system if you change the fluid or perform work
on the system.
1. Disengage the PTO and set the parking brake.
2. Shut off the engine and wait for all moving parts to
stop before leaving the operating position.
3. Raise the rear of the machine onto jack stands high
enough to raise the drive wheels off the ground.
4. Start the engine and move the throttle control to the
idle position.
Note:
If the drive wheel does not rotate, it is possible
to assist the purging of the system by carefully rotating
the tire in the forward direction.
5. Check the hydraulic fluid level as it drops, and add fluid
as required to maintain the proper level.
6. Repeat this procedure for the opposite wheel.
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