Toro Groundsmaster 4300-D Service Manual page 135

Test Procedure
Groundsmaster ® 4300-D
16226SL Rev C
1. Ensure that the hydraulic fluid is at normal operating temperature by
operating the machine for at least 10 minutes.
2. Drive the machine slowly in a figure eight on a flat level surface.
A. There should be no shaking or vibration in the steering wheel or rear
wheels.
B. The steering wheel movements should be followed immediately by
a corresponding rear wheel movement without the steering wheel
continuing to turn.
3. Stop unit with the engine running. Turn the steering wheel with small quick
movements in both directions. Let go of the steering wheel after each
movement.
A. The steering control valve should respond to each steering wheel
movement.
B. When steering wheel is released, steering control should return to the
neutral position with no additional turning.
4. If either of these performance tests indicate a steering problem, determine if
the steering cylinder is damaged using the following procedure:
A. Park the machine on a level surface with the PTO switch off, lower the
cutting units, and set the parking brake.
B. With the engine running, turn the steering wheel to the right (clockwise)
until the steering cylinder rod is fully extended and shut off the engine.
C. Read all Warning, Cautions, and precautions listed at the beginning of
this section.
D. Clean the fitting and hose end, disconnect the hydraulic hose from the
fitting on the rod end of the steering cylinder.
E. Use an elbow or a tee fitting with a hole plugged and install a pressure
gauge at the end of the disconnected hose.
F. With the engine off, continue turning the steering wheel to the right
(clockwise) with the steering cylinder fully extended. Monitor the open
fitting on the steering cylinder as the wheel is turned. If the hydraulic fluid
comes out of the fitting while turning the steering wheel to the left, the
steering cylinder has internal leakage and should be repaired or replaced.
5. The steering circuit relief valve located in the steering control valve can be
tested with the pressure gauge installed in the same location as the steering
cylinder test (step 4) as follows:
A. Start the engine and run it at low-idle speed. Check for hydraulic-fluid
leaks from the test connections and correct before continuing the test.
B. Set the engine speed to approximately 2,000 rpm. Use the InfoCenter to
check that the engine speed is correct.
Hold the steering wheel at full lock only long enough to get a
system pressure reading. Holding the steering wheel against the
stop for an extended period may damage the steering control
valve.
C. Monitor the pressure gauge carefully when turning the steering wheel for
a right hand turn (clockwise) and holding.
IMPORTANT
Page 4–73 Hydraulic System: Testing the Hydraulic System