SERVICE
Service Hydraulics
Changing Hydraulic Oil and Filters, ZT-3100
1. Park machine safely. Engage the parking brake.
2. Allow engine and transaxles to cool.
3. Jack machine up from rear. Use blocking to support machine.
4. Remove both rear tires. Apply the bypass valves for both transaxles.
5. Place drain pan under machine. The pan should hold more than 1.5 gallons
or 6 quarts.
Hydraulic oil filter.
31
Transaxle drain plug.
The transaxles are designed with an external filter for ease of maintenance.
To ensure constant fluid quality levels and longer life, an initial oil and
filter change at 75 hours, then every 400 hours thereafter.
The following procedure can be performed with the transaxles installed
in the machine, and the machine on level ground. Engage the parking brake and
apply the bypass valve for each transaxle.
6. Remove the two filter guard screws and filter guard. Clean any loose debris
from around the perimeter of the filter. Place drain pan beneath the oil filter.
7. Remove the oil filter from the transaxle. Dispose of used filter properly.
8. After the oil has drained, wipe the filter base surface off and apply a film of new oil
to the gasket of the new replacement filter.
9. Install the new filter by hand, turn 3/4 to one full turn after the filter gasket contacts
the filter base surface. Do not use a wrench.
10. Re-install the filter guard with two screws. Torque screws to 65 in. lbs.
11. Repeat steps 6-10 on the opposite side transaxle drive.
12. Remove the top purge port plug from the left and right side transaxles.
13. Remove the drain plugs from both transaxles and allow to drain,
when empty, replace plugs and torque to 180 in. lbs.
14. Remove the cap from the expansion tank, fill with 15W50 motor oil until oil just
appears at the bottom of each transaxle’s purge port (approximately 2 qts. per
transaxle, 4 qts. total). Install the purge port plug into each transaxle as the oil level
reaches this port.
