Toro Groundsmaster 7210, Service Manual

Page: 104 / 342

Perform the wheel motor efficiency test if you identify a traction circuit problem.
This test determines if a wheel motor has excessive internal leakage and wear.
Note: Over a period of time, a wheel motor can wear internally. A worn motor
may bypass the hydraulic fluid to its case drain that reduces the motor efficiency.
After sometime, sufficient fluid loss causes the wheel motor to stall under
heavy load conditions. Continued operation with a worn, inefficient motor can
generate excessive heat, cause damage to the seals and other components in
the hydraulic system and affect overall machine performance.
Test Procedure
1. Ensure that the hydraulic fluid is at normal operating temperature.
2. Ensure that the traction drive is correctly adjusted for the N
EUTRAL
position.
WARNING
Before disconnecting or doing any work on the hydraulic system,
release all the pressure in the system; refer to
Releasing Pressure
from the Hydraulic System (page 4–11) .
3. Park the machine on a level surface, lower the cutting deck (or implement),
shut off the engine, and set the parking brake.
4. Read all Warning, Cautions, and precautions listed at the beginning of this
section.
5. Attach a heavy chain to the rear of the machine frame and an immovable
object to prevent the machine from moving during testing. As an alternative,
raise the machine and support it with jack stands so that the 2 rear wheels
are off the ground.
6. Disconnect the wire harness connector from the parking brake sensor; refer
to the Parking Brake Sensor (page 5–33) . Install a jumper wire across the
harness connector terminals and set the parking brake to allow traction
circuit operation.
7. Clean the transmission area around the traction circuit hoses on the top of
the transmission ( Figure 43 ). Determine which wheel motor is to be tested.
8. Disconnect the hydraulic hose from the transmission pump outlet fitting to
test the wheel motor ( Figure 43 ):
Wheel Motor to be Tested Pump Outlet
Right side motor Port A
Left side motor Port C
9. Install a hydraulic tester (pressure and flow) in series between the pump
outlet fitting and disconnected hose. Ensure that the tester flow arrow points
from the pump outlet and toward the hose. Ensure that the flow control valve
on the tester is fully open.
10. Start the engine and run it at low-idle speed (1,400 rpm) . Check for
hydraulic-fluid leaks from test connections and correct before continuing
the test.
Hydraulic System: Testing the Hydraulic System Page 4–44 Groundsmaster 7210
16222SL Rev C