Service Manual

Mid-Size Walk Behind Service Manual 5 - 27
HYDRAULIC DRIVE SYSTEMS
2. Install new ‘O’ rings on the motor fittings. Install
the hose fittings.
3. Align the wheel hub to the woodruff key on the
motor shaft. Slide hub into position and thread the
nut onto the shaft to hold the hub in position.
Slide the wheel onto the hub and snug up the lug
nuts. Apply the parking brake and tighten the hub
nut to 165 ft. lbs. (224 N-m) and install the cotter
key.
4. Reconnect the return and supply lines to the
reservoir and refill with fresh oil until the level is
1/4” (6mm) below the top baffle (Figure 123).
Figure 118
m-4280
5. Bleed air from the system:
6. Start the engine and run at idle speed. Engage
traction on one side and spin the wheel by hand.
7. When the wheel begins to spin on its own, keep it
engaged until wheel drives smoothly (minimum 2
minutes).
8. Check hydraulic fluid level as it drops and add as
required to maintain proper level.
9. Repeat procedure on opposite wheel.
10. Lower unit to the ground and tighten lug nuts to 85
ft. lbs. (115 N-m). Tighten lug nuts in a crisscross
pattern from top to bottom - left to right.
Pump Removal
1. Thoroughly clean the area around the pump and
hydraulic fittings to prevent dirt from entering the
system.
2. Remove the drive pulley.
3. Use the cold start ring to remove tension from the
pump drive belt.
4. Loosen the two set screws and slide the pulley off
the pump shaft. Remove the woodruff key from
the shaft (Figure 119).
Figure 119
0602-50
Note: When installing the pulley, slide it onto the shaft
until the end of the shaft is flush with the bottom of the
counter bore in the pulley.
5. Drain the fluid reservoir by removing the return
and supply lines.
(1) Cap
(2) Baffle
(3) Fluid level - full