Replace Wheel Motor; Hydraulic Deck Lift Pressure Test; Replace Lift Valve - Gravely Promaster 260Z Service Manual

REPLACE WHEEL MOTOR

Each drive wheel is mounted to a hydraulic drive motor.
The drive motors are maintenance free. In the event of
a failure, the drive motors should be replaced.
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1
1. Hub
Figure 27
To Replace a Drive Motor
1. Loosen the wheel lugs 1/4 turn.(Figure 27)
2. Jack the drive wheels off the ground and securely
support the unit.
3. Remove the wheel.
4. Unscrew the axle bolt at the center of the hub and
remove the hub. The hub is a taper fit on the axle.
Use a wheel puller to assist in removal.
5. Mark the hydraulic lines and remove.
CAUTION: Some fluid will leak out. Clean up
any spills.
6. Unscrew the two bottom bolts and pull the
hydraulic motor out.
7. Slide the motor into place and secure with two
bottom bolts. Apply Loctite to bolts
8. Reattach hydraulic lines to proper ports and
tighten.
9. Clean the axle and the inside of the hub. Place hub
over axle and lightly tap into position. Screw the
axle nut onto the axle and tighten to 300-400 ft. lbs.
(406-542 Nm)
10.Position wheel on hub and insert lug nuts finger
tight.
11.Tighten lug nuts using the pattern shown in Figure
28.
12.Lower the unit to the ground and start the engine.
Drive forward twenty feet and stop the engine.
Check the hydraulic fluid level. The dipstick should
read between the high and low markings.
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2
PD2231
2. Hydraulic motor
4
2

HYDRAULIC DECK LIFT PRESSURE TEST

Use this test for trouble shooting the hydraulic lift
system if the lift becomes sluggish or loss of lift occurs.
1. Place unit into the service position.
2. Clean and disconnect the hydraulic hose at the
lower side of hydraulic lift valve (Figure 29) and
install a 1500 psi minimum hydraulic pressure
gauge using a tee fitting.
3. Have someone depress center of seat to activate
seat switch.
4. Start the engine and run at about 3/4 throttle or
faster.
5. Move the deck lift lever to the raise position and
hold. Relief pressure should be 650 psi minimum
from the Hydro-Gear auxiliary pump.
6. If the mower deck height creeps down during
operation, the hydraulic valve, cylinder or hydraulic
hose is faulty. You will need to check the condition
of the hoses and verify that there are no hydraulic
leaks and the fittings are tight.
7. Remove the valve.

REPLACE LIFT VALVE

The lift valve is located inside the chassis on the left
side. See Figure 29.
1. Place hood in full service position.
2. Clean hose fittings, mark hoses for position and
disconnect from valve.
CAUTION: Some hydraulic fluid will leak out
of the hoses. Clean up any spills.
3. Loosen mounting bolts and remove valve.
4. Mount new valve and tighten bolts.
5. Connect hoses to proper ports.
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3
5
Figure 28
OK 0630